Given the novel scientific setting in which this case arises and the considerable interest this litigation has engendered within the medical research community and the public generally, it is easy to lose sight of the fact that the specific allegations on which the complaint in this case rests are quite unusual, setting this matter apart from the great majority of instances in which donated organs or cells provide the raw materials for the advancement of medical science and the development of new and beneficial medical products. Ordinarily, when a patient consents to the use of a body part for scientific purposes, the potential value of the excised organ or cell is discovered only through subsequent experimentation or research, often months or years after the removal of the organ. In this case, however, the complaint alleges that plaintiff’s doctor recognized the peculiar research and commercial value of plaintiff’s cells before their removal from plaintiff’s body. Despite this knowledge, the doctor allegedly failed to disclose these facts or his interest in the cells to plaintiff, either before plaintiff’s initial surgery or throughout the ensuing seven-year period during which the doctor continued to obtain additional cells from plaintiff’s body in the course of periodic medical examinations.
The majority opinion, of course, is not oblivious to the significance of these unusual allegations. It relies on those allegations in concluding that the complaint states a cause of action for breach of fiduciary duty. I concur fully in that holding.
*151When it turns to the conversion cause of action, however, the majority opinion fails to maintain its focus on the specific allegations before us. Concerned that the imposition of liability for conversion will impede medical research by innocent scientists who use the resources of existing cell repositories—a factual setting not presented here—the majority opinion rests its holding, that a conversion action cannot be maintained, largely on the proposition that a patient generally possesses no right in a body part that has already been removed from his body. Here, however, plaintiff has alleged that defendants interfered with his legal rights before his body part was removed. Although a patient may not retain any legal interest in a body part after its removal when he has properly consented to its removal and use for scientific purposes, it is clear under California law that before a body part is removed it is the patient, rather than his doctor or hospital, who possesses the right to determine the use to which the body part will be put after removal. If, as alleged in this case, plaintiff’s doctor improperly interfered with plaintiff’s right to control the use of a body part by wrongfully withholding material information from him before its removal, under traditional common law principles plaintiff may maintain a conversion action to recover the economic value of the right to control the use of his body part. Accordingly, I dissent from the majority opinion insofar as it rejects plaintiff’s conversion cause of action.
I
To begin with, I concur fully in the majority’s conclusion that the facts alleged in the complaint state a cause of action for breach of fiduciary duty against Dr. Golde. As the majority persuasively explains, because a physician’s research activities and related commercial ventures may potentially affect his or her professional judgment, a physician has an obligation to disclose such personal interests to his patient. In this case, the complaint clearly alleges that Dr. Golde failed to fulfill this duty.
With respect to the additional defendants—the Regents of the University of California (hereafter Regents), Shirley G. Quan, Genetics Institute, Inc. (hereafter Genetics Institute), and Sandoz Pharmaceuticals Corporation (hereafter Sandoz)—I cannot fully join in the majority’s conclusion. Although I agree that the trial court erred in sustaining these defendants’ demurrers to the breach of fiduciary duty cause of action without leave to amend, in my view the majority’s ruling with respect to these defendants is more equivocal than is warranted. (See maj. opn., ante, pp. 133-134.) As the majority recognizes, the breach of fiduciary duty alleged in the complaint encompasses postoperative conduct—for example, the periodic withdrawal of blood, blood serum, bone marrow aspirate and sperm samples from plaintiff, requiring plaintiff to travel from Seattle to the Medical Center of *152the University of California at Los Angeles (hereafter UCLA Medical Center)—which continued until September 1983. By that date, according to the complaint, all of the defendants, including Genetics Institute and Sandoz, were already involved in the commercial venture. Despite the “boilerplate” nature of some of the agency allegations in the complaint (see maj. opn., ante, p. 134, fn. 12), the complaint’s allegations, viewed in their entirety,1 charge sufficient complicity on the part of all defendants in the allegedly improper postoperative conduct to survive a demurrer. If, after discovery, it becomes clear that the additional defendants bear no responsibility for either the original or continuing breach of fiduciary duty, those defendants can, of course, move for summary judgment on this count. At the present pleading stage, however, it is premature to absolve any of the defendants of liability for breach of fiduciary duty.
I disagree, however, with the suggestion in the dissenting opinion that defendants will be able to avoid all liability under the breach-of-fiduciary-duty theory simply by showing that plaintiff would have proceeded with the surgical removal of his diseased spleen even if defendants had disclosed their research and commercial interest in his cells. (See dis. opn., post, pp. 179-180.) In the first place, because the alleged breach of fiduciary duty encompasses the postoperative conduct of defendants as well as the presurgical failure to disclose, plaintiff will clearly be entitled to recover under a breach-of-fiduciary-duty theory by establishing that he would not have consented to some or all of the extensive postoperative medical procedures if he had been fully aware of defendants’ research and economic interests and motivations. Second, and more generally, in this context—unlike in the traditional “informed consent” context of Cobbs v. Grant (1972) 8 Cal.3d 229 [104 Cal.Rptr. 505, 502 P.2d 1]—a plaintiff should not be required to establish that he would not have proceeded with the medical treatment in question if his physician had made full disclosure, but only that the doctor’s wrongful failure to disclose information proximately caused the plaintiff some type of compensable damage. The majority does not attempt to identify in advance of trial the various kinds of damage or injury for which *153plaintiff may properly recover in his breach-of-fiduciary-duty action, and that may be understandable. Nonetheless, it is worth noting that, in appropriate circumstances, punitive as well as compensatory damages would clearly be recoverable in such an action. Accordingly, the dissent underestimates the potential efficacy of the breach-of-fiduciary-duty cause of action in dismissing the action as a “paper tiger.” (Dis. opn., post, p. 180.)
II
With respect to the conversion cause of action, I dissent from the majority’s conclusion that the facts alleged in this case do not state a cause of action for conversion.
If this were a typical case in which a patient consented to the use of his removed organ for general research purposes and the patient’s doctor had no prior knowledge of the scientific or commercial value of the patient’s organ or cells, I would agree that the patient could not maintain a conversion action. In that common scenario, the patient has abandoned any interest in the removed organ and is not entitled to demand compensation if it should later be discovered that the organ or cells have some unanticipated value. I cannot agree, however, with the majority that a patient may never maintain a conversion action for the unauthorized use of his excised organ or cells, even against a party who knew of the value of the organ or cells before they were removed and breached a duty to disclose that value to the patient. Because plaintiff alleges that defendants wrongfully interfered with his right to determine, prior to the removal of his body parts, how those parts would be used after removal, I conclude that the complaint states a cause of action under traditional, common law conversion principles.
In analyzing the conversion issue, the majority properly begins with the established requirements of a common law conversion action, explaining that a plaintiff is required to demonstrate an actual interference with his “ownership or right of possession” in the property in question. (Maj. opn., ante, p. 136.) Although the majority opinion, at several points, appears to suggest that a removed body part, by its nature, may never constitute “property” for purposes of a conversion action (see maj. opn., ante, pp. 138, 140), there is no reason to think that the majority opinion actually intends to embrace such a broad or dubious proposition. If, for example, another medical center or drug company had stolen all of the cells in question from the UCLA Medical Center laboratory and had used them for its own benefit, there would be no question but that a cause of action for conversion would properly lie against the thief, and the majority opinion does not suggest otherwise. Thus, the majority’s analysis cannot rest on the broad proposition that a removed body part is not property, but rather rests on the *154proposition that a patient retains no ownership interest in a body part once the body part has been removed from his or her body.
The majority opinion fails to recognize, however, that, in light of the allegations of the present complaint, the pertinent inquiry is not whether a patient generally retains an ownership interest in a body part after its removal from his body, but rather whether a patient has a right to determine, before a body part is removed, the use to which the part will be put after removal. Although the majority opinion suggests that there are “reasons to doubt” that a patient retains “any” ownership interest in his organs or cells after removal (maj. opn., ante, p. 137), the opinion fails to identify any statutory provision or common law authority that indicates that a patient does not generally have the right, before a body part is removed, to choose among the permissible uses to which the part may be put after removal. On the contrary, the most closely related statutory scheme—the Uniform Anatomical Gift Act (Health & Saf. Code, § 7150 et seq.)2 — makes it quite clear that a patient does have this right.
The Uniform Anatomical Gift Act is a comprehensive statutory scheme that was initially adopted in California in 1970 and most recently revised in 1988. Although that legislation, by its terms, applies only to a donation of all or part of a human body which is “to take effect upon or after [the] death [of the donor]” (§ 7150.1, subd. (a))—and thus is not directly applicable to the present case which involves a living donor—the act is nonetheless instructive with regard to this state’s general policy concerning an individual’s authority to control the use of a donated body part. The act, which authorizes an anatomical gift to be made, inter alia, to “[a] hospital [or a] physician[,] ... for transplantation, therapy, medical or dental education, research or advancement of medical or dental science” (§ 7153, subd. (a)(1)), expressly provides that such a gift “may be made to a designated donee or without designating a donee” (§ 7153, subd. (b)) and also that the donor may make such a gift “for any of the purposes [specified in the statute or may] limit an anatomical gift to one or more of those purposes . . . .” (§ 7150.5, subd. (a).) Thus, the act clearly recognizes that it is the donor of the body part, rather than the hospital or physician who receives the part, who has the authority to designate, within the parameters of the statutorily authorized uses, the particular use to which the part may be put.
Although, as noted, the Uniform Anatomical Gift Act applies only to anatomical gifts that take effect on or after the death of the donor, the general principle of “donor control” which the act embodies is clearly not limited to that setting. In the transplantation context, for example, it is *155common for a living donor to designate the specific donee—often a relative—who is to receive a donated organ. If a hospital, after removing an organ from such a donor, decided on its own to give the organ to a different donee, no one would deny that the hospital had violated the legal right of the donor by its unauthorized use of the donated organ. Accordingly, it is clear under California law that a patient has the right, prior to the removal of an organ, to control the use to which the organ will be put after removal.
It is also clear, under traditional common law principles, that this right of a patient to control the future use of his organ is protected by the law of conversion. As a general matter, the tort of conversion protects an individual not only against improper interference with the right of possession of his property but also against unauthorized use of his property or improper interference with his right to control the use of his property. Sections 227 and 228 of the Restatement Second of Torts specifically provide in this regard that “[o]ne who uses a chattel in a manner which is a serious violation of the right of another to control its use is subject to liability to the other for conversion” and that “[o]ne who is authorized to make a particular use of a chattel, and uses it in a manner exceeding the authorization, is subject to liability for conversion to another whose right to control the use of the chattel is thereby seriously violated.” California cases have also long recognized that “unauthorized use” of property can give rise to a conversion action. (See Hollywood M. P. Equipment Co. v. Purer (1940) 16 Cal.2d 184, 189 [105 P.2d 299]. See generally 5 Witkin, Summary of Cal. Law (9th ed. 1988) Torts, § 622, p. 716.)
The application of these principles to the present case is evident. If defendants had informed plaintiff", prior to removal, of the possible uses to which his body part could be put and plaintiff" had authorized one particular use, it is clear under the foregoing authorities that defendants would be liable for conversion if they disregarded plaintiff’s decision and used the body part in an unauthorized manner for their own economic benefit. Although in this case defendants did not disregard a specific directive from plaintiff with regard to the future use of his body part, the complaint alleges that, before the body part was removed, defendants intentionally withheld material information that they were under an obligation to disclose to plaintiff and that was necessary for his exercise of control over the body part; the complaint also alleges that defendants withheld such information in order to appropriate the control over the future use of such body part for their own economic benefit. If these allegations are true, defendants clearly improperly interfered with plaintiff’s right in his body part at a time when he had the authority to determine the future use of such part, thereby misappropriating plaintiff’s right of control for their own advantage. Under *156these circumstances, the complaint fully satisfies the established requirements of a conversion cause of action.
As already noted, the majority maintains that there are a number of “reasons to doubt” that a patient retains any legally protectible interest in his organs after removal (maj. opn., ante, p. 137), but none of these reasons withstands scrutiny. The majority first relies on the fact that “no reported judicial decision supports Moore’s claim, either directly or by close analogy.” (Maj. opn., ante, p. 137.) By the same token, however, there is no reported judicial decision that rejects such a claim. This is simply a case of first impression. And while the majority goes on to emphasize that it is the “specialized statutes” dealing with human biological materials to which the court should look for guidance in determining whether a patient has any legal rights with respect to an organ after removal (maj. opn., ante, p. 137), the majority fails to recognize that the Uniform Anatomical Gift Act, as we have seen, expressly confirms a patient’s right to designate, prior to removal, the use to which a body part will be put. (See ante, pp. 154-155.)
The majority next relies on the provisions of section 7054.4,3 a statute that addresses the potential health hazards posed by the improper disposal of human body parts, reasoning that this statute “drastically limits a patient’s control over excised cells.” (Maj. opn., ante, p. 140.) While I agree with the majority that section 7054.4 should reasonably be interpreted to apply to body parts removed from a living patient as well as from dead bodies, the statute nonetheless provides absolutely no support for the majority’s conclusion. Although section 7054.4 limits a patient’s control over an excised body part in the sense that it prohibits him from taking the removed part to his home and keeping it on his mantel, the statute certainly does not suggest that a patient does not have the right to choose among the legally permissible uses of his organ. Similarly, there is nothing in section 7054.4 which indicates that a doctor or medical facility that removes a patient’s organ possesses any greater right than the patient himself to choose the further use to which the removed organ will be put. Since the majority does not suggest that the provisions of section 7054.4 should be interpreted to prohibit the research or commercial activities at issue in this case—and I agree that the statute cannot reasonably be interpreted to prohibit such use—I cannot understand how section 7054.4 provides any assistance to the majority’s argument.
*157Finally, the majority maintains that plaintiff’s conversion action is not viable because “the subject matter of the Regents’ patent—the patented cell line and the products derived from it—cannot be Moore’s property.” (Maj. opn., ante, p. 141.) Even if this is an accurate statement of federal patent law, it does not explain why plaintiff may not maintain a conversion action for defendants’ unauthorized use of his own body parts, blood, blood serum, bone marrow, and sperm. Although the damages which plaintiff may recover in a conversion action may not include the value of the patent and the derivative products, the fact that plaintiff may not be entitled to all of the damages which his complaint seeks does not justify denying his right to maintain any conversion action at all. Similarly, although the question whether plaintiff’s cells are “unique” may well affect the amount of damages plaintiff will be able to recover in a conversion action, the question of uniqueness has no proper bearing on plaintiff’s basic right to maintain a conversion action; ordinary property, as well as unique property, is, of course, protected against conversion.
Thus, unlike the majority, I conclude that under established common law principles the facts alleged in the complaint state a cause of action for conversion.4
Ill
Although the majority opinion does not acknowledge that plaintiff’s conversion action is supported by existing common law principles, its reasoning suggests that the majority would, in any event, conclude that considerations of public policy support a judicially crafted limitation on a patient’s right to sue anyone involved in medical research activities for conversion of a patient’s excised organs or cells. (Maj. opn., ante, pp. 142-147.) For a number of reasons, I cannot agree that this court should carve out such a broad immunity from general conversion principles.
One of the majority’s principal policy concerns is that “[t]he extension of conversion law into this area will hinder research by restricting access to the *158necessary raw materials”—the thousands of cell lines and tissues already in cell and tissue repositories. (Maj. opn., ante, p. 144.) The majority suggests that the “exchange of scientific materials, which still is relatively free and efficient, will surely be compromised if each cell sample becomes the potential subject matter of a lawsuit.” (Maj. opn., ante, p. 145.)
This policy argument is flawed in a number of respects. First, the majority’s stated concern does not provide any justification for barring plaintiff from bringing a conversion action against a party who does not obtain organs or cells from a cell bank but who directly interferes with or misappropriates a patient’s right to control the use of his organs or cells. Although the majority opinion suggests that the availability of a breach-of-fiduciary-duty cause of action obviates any need for a conversion action against this category of defendants (see maj. opn., ante, p. 147), the existence of a breach-of-fiduciary-duty cause of action does not provide a complete answer. Even if in this case plaintiff may obtain the same remedy against such defendants under a breach-of-fiduciary-duty theory as he could under a conversion cause of action, in other factual settings an unlawful interference with a patient’s right to control the use of his body part may occur in the absence of a breach of fiduciary duty. For example, if a patient donated his removed cells to a medical center, reserving the right to approve or disapprove the research projects for which the cells would be used, and if another medical center or a drug manufacturer stole the cells after removal and used them in an unauthorized manner for its own economic gain, no breach-of-fiduciary-duty cause of action would be available and a conversion action would be necessary to vindicate the patient’s rights. Under the majority’s holding, however, the patient would have no right to bring a conversion action, even against such a thief. As this hypothetical illustrates, even if there were compelling policy reasons to limit the potential liability of innocent researchers who use cells obtained from an existing cell bank, those policy considerations would not justify the majority’s broad abrogation of all conversion liability for the unauthorized use of body parts.
Second, even with respect to those persons who are not involved in the initial conversion, the majority’s policy arguments are less than compelling. To begin with, the majority’s fear that the availability of a conversion remedy will restrict access to existing cell lines is unrealistic. In the vast majority of instances the tissues and cells in existing repositories will not represent a potential source of liability because they will have come from patients who consented to their organ’s use for scientific purposes under circumstances in which such consent was not tainted by a failure to disclose the known valuable nature of the cells. Because potential liability under a conversion theory will exist in only the exceedingly rare instance in which a doctor knowingly concealed from the patient the value of his body part or *159the patient’s specific directive with regard to the use of the body part was disregarded, there is no reason to think that application of settled conversion law will have any negative effect on the primary conduct of medical researchers who use tissue and cell banks.
Furthermore, even in the rare instance—like the present case—in which a conversion action might be successfully pursued, the potential liability is not likely “to destroy the economic incentive to conduct important medical research,” as the majority asserts. (Maj. opn., ante, p. 146.) If, as the majority suggests, the great bulk of the value of a cell line patent and derivative products is attributable to the efforts of medical researchers and drug companies, rather than to the “raw materials” taken from a patient (maj. opn., ante, pp. 141-142), the patient’s damages will be correspondingly limited, and innocent medical researchers and drug manufacturers will retain the considerable economic benefits resulting from their own work. Under established conversion law, a “subsequent innocent converter” does not forfeit the proceeds of his own creative efforts, but rather “is entitled to the benefit of any work or labor that he has expended on the [property] . . . .” (1 Harper et al., The Law of Torts (2d ed. 1986) § 2.34, p. 234. See generally Rest. 2d Torts, § 927, corns, f, g.)
Finally, the majority’s analysis of the relevant policy considerations tellingly omits a most pertinent consideration. In identifying the interests of the patient that are implicated by the decision whether to recognize a conversion cause of action, the opinion speaks only of the “patient’s right to make autonomous medical decisions” (maj. opn., ante, p. 143) and fails even to mention the patient’s interest in obtaining the economic value, if any, that may adhere in the subsequent use of his own body parts. Although such economic value may constitute a fortuitous “windfall” to the patient (maj. opn., ante, p. 147), the fortuitous nature of the economic value does not justify the creation of a novel exception from conversion liability which sanctions the intentional misappropriation of that value from the patient.
This last point reveals perhaps the most serious flaw in the majority’s public policy analysis in this case. It is certainly arguable that, as a matter of policy or morality, it would be wiser to prohibit any private individual or entity from profiting from the fortuitous value that adheres in a part of a human body, and instead to require all valuable excised body parts to be deposited in a public repository which would make such materials freely available to all scientists for the betterment of society as a whole. The Legislature, if it wished, could create such a system, as it has done with respect to organs that are donated for transplantation. (See § 7155, subd. (a); Pen. Code, § 367f. See also 42 U.S.C. § 274e.) To date, however, the Legislature has not adopted such a system for organs that are to be used for *160research or commercial purposes,5 and the majority opinion, despite some oblique suggestions to the contrary (see maj. opn., ante, pp. 144-145), emphatically does not do so by its holding in this case. Justice Arabian’s concurring opinion suggests that the majority’s conclusion is informed by the precept that it is immoral to sell human body parts for profit. (See cone, opn., ante, p. 149.) But the majority’s rejection of plaintiff’s conversion cause of action does not mean that body parts may not be bought or sold for research or commercial purposes or that no private individual or entity may benefit economically from the fortuitous value of plaintiff’s diseased cells. Far from elevating these biological materials above the marketplace, the majority’s holding simply bars plaintiff, the source of the cells, from obtaining the benefit of the cells’ value, but permits defendants, who allegedly obtained the cells from plaintiff by improper means, to retain and exploit the full economic value of their ill-gotten gains free of their ordinary common law liability for conversion.
Because I conclude that plaintiff’s complaint states a cause of action for conversion under traditional common law principles, I dissent from the majority opinion insofar as it rejects such a claim.
In addition to the very general agency allegations quoted by the majority, the complaint also alleges (1) that “Golde, both in his capacity as a physician and in his separate capacity as a researcher engaged in commercial activities, was an employee, officer and/or agent of. . . [t]he Regents,” (2) that “at all times after on or about 1980, continuing through the present, . . . Golde, both in his capacity as a physician in the physician-patient relationship with plaintiff, and as a researcher and investor engaged in the commercial exploitation of the products extracted from plaintiff, was an employee, officer, investor, advisor, consultant and/or agent of. . . Genetics Institute [and]. . . Sandoz,” and (3) that “[i]n these applicable capacities, . . . Golde acted with the knowledge and support of. . . [t]he Regents, . . . Genetics Institute, [and] Sandoz . . . , which knew or should have known of. . . the means by which . . . Golde had obtained access to, and continued to have access to, plaintiff’s [b]lood and [b]odily [sjubstances, and through their actions and compensation of. . . Golde, ratified or approved . . . Golde’s activities in this regard.”
Unless otherwise noted, all section references are to the Health and Safety Code.
Section 7054.4 provides: “Notwithstanding any other provision of law, recognizable anatomical parts, human tissues, anatomical human remains, or infectious waste following conclusion of scientific use shall be disposed of by interment, incineration, or any other method determined by the state department [of health services] to protect the public health and safety.”
The majority opinion inaccurately characterizes this opinion as proposing the creation of “a new cause of action” that would “extend conversion liability” by requiring the allegation of a new element of fraud in addition to the traditional elements of a conversion cause of action. (See maj. opn., ante, p. 146, fn. 41.) As explained above, my position is that the facts alleged in the present complaint state a cause of action for conversion under traditional, well-established common law principles. Contrary to the implication of the majority’s assertion, it requires no extension of existing common law principles to recognize that a conversion action will lie where the facts alleged in a complaint demonstrate that the defendant obtained the plaintiff’s consent by fraud. (See generally 5 Witkin, Summary of Cal. Law (9th ed. 1988) Torts, § 621, p. 715; Rest.2d Torts, §§ 221, 229.) In reality, it is the majority opinion that departs from established common law principles by fashioning a novel exception that shields the defendants in this case from the ordinary reach of conversion liability.
As the dissent points out (dis. opn., post, pp. 176-177), although the Uniform Anatomical Gift Act expressly authorizes the gift of body parts for the purposes of “transplantation, therapy, medical or dental education, research, or advancement of medical or dental science” (§ 7153, subd. (a) (1)), the provision of the act that is specifically concerned with the purchase or sale of a body part for valuable consideration only prohibits a person from knowingly purchasing or selling a body part “for transplantation [or] therapy” (§ 7155, subd. (a)), and does not extend its prohibition to purchases or sales of body parts for the other purposes authorized by the statute, i.e., for research, education, or the advancement of medical science.
A comment to the section of the model Uniform Anatomical Gift Act on which section 7155 was based explains the basis for the prohibition on sale of body parts for transplantation or therapy: “ ‘Altruism and a desire to benefit other members of the community are important moral reasons which motivate many to donate. Any perception on the part of the public that transplantation unfairly benefits those outside the community, those who are wealthy enough to afford transplantation, or that it is undertaken primarily with an eye toward profit rather than therapy will severely imperil the moral foundations, and thus the efficacy of the system.’ ” (8A, West’s U. Laws Annot. (1990 pocket pt.) Anatomical Gift Act (1987) § 10, p. 25.) The drafters of the provision apparently concluded that this rationale did not warrant extending the prohibition on purchase or sale to the sale of body parts that are to be used for any of the statutorily authorized purposes other than transplantation or therapy.
Given the current provisions of the Uniform Anatomical Gift Act, there is no basis to conclude that there is a general public policy in this state prohibiting hospitals or medical centers from giving, or prohibiting patients from receiving, valuable consideration for body parts which are to be used for medical research or the advancement of medical science.