concurring-in-part, dissenting-in-part.
While I concur with the majority’s decision to remand this case to the district court to evaluate infringement under the doctrine of equivalents, I respectfully dissent with regard to the affirmance of the claim construction and grant of summary judgment of no literal infringement.
With respect to claim construction, I remain unpersuaded by the majority’s view that “intracellular marker substance” *1170does not encompass portions of an antigen located inside a cell. The majority concludes that “marker substance” is an equivalent term for “antigen,” when in view of the intrinsic record, I believe “marker substance” bears a broader meaning. First, the claims expressly recognize that the “marker substance” may correspond to only a fragment, i.e., sub-unit, of an antigen. See '559 patent, claim 1 (“when said antibody is an antibody specific to human chlorionic [sic] gonadotropin or its beta-subunit, said radioisotope is other than Te-99m”); claim 17 (narrowing the scope of “marker substance,” recited in claim 1, to exclude a specific sub-unit of an antigen). Further, the specification expressly acknowledges that a “sub-unit of a tumor-associated marker” may be “advantageously used to raise antibodies having higher tumor specificity.” Id., col. 2, ll. 51-53. Moreover, the specification states that “such marker substances ” that are “useful in the present invention include, but are not limited to, alphafetoprotein (AFP), human chorionic gonadotropin (HCG) and/ or its beta-subunit (HCG-beta).” Id., col. 2, ll. 57-61 (emphases added). The specification and the claims clearly signal that part of an antigen, i.e., the epitope, may correspond to the “marker substance.” My understanding of “marker substance,” as derived from the intrinsic record is consistent with testimony by Goldenberg’s expert, Dr. Primus, who testified that “any substance that has in this case an epitope, a marker, which an antibody sees that occurs within the cytoplasm of the cell, is an intracellular marker substance.”
The appellees submit and the majority agrees that the beta sub-unit óf HCG does not correspond to a portion of an antigen, but rather is an antigen itself. The specification acknowledges that HCG is an antigen made up of smaller constituents, namely, an ■ alpha and beta sub-unit. Id. The majority rejects, in my opinion, the seemingly inescapable conclusion that the beta sub-unit, identified by the specification to be a “marker substance,” composes a portion of the HCG antigen. The majority cites no intrinsic evidence, much less the extrinsic evidence of any expert, to support its position that the beta sub-unit, which undeniably forms only a part of the HCG antigen, is recognized by those skilled in the relevant art to qualify as an antigen.
The prosecution history, which the majority discusses, ante at 1165, is of little help to its proposed claim construction. The patentee had attempted to overcome a double patenting rejection by arguing that the method and compositions claimed by the '261 application (the predecessor to the application that became the '559 patent) are distinguishable from the '262 application (the predecessor to the '744 patent application) on the basis that the '261 application relates to “antibodies to intracellular tumor associated antigens” whereas the '262 application relates to “cell surface antigen[s]” that are “located on the surface of the tumor cell.” (Emphases in original). In other words, the pertinent novelty and difference between the '261 application and the '262 application and prior art lay in the site of tumor localization. As explained by the patent applicant, “[bjefore the work of the present inventor, the art did not know that antibodies to ... intracellular [tumor associated] antigens, e.g., human chorionic gonadotropic (HCG) and alpha-fetoprotein (AFP) could be used successfully for tumor localization and therapy.” The specification further informs us that in addition to HCG and AFP, other “marker substances to which specific antibodies may be raised which are useful in the present invention include, but are not limited to ... [the beta-subunit of HCG].” '559 patent, col. 2,11. 57-61. “Occasionally, *1171a sub-unit of a tumor associated marker is advantageously used to raise antibodies having higher tumor-specificity.” Id., col. 2, 11. 51-54 (emphasis added). The distinguishing statement relied on by the majority in the prosecution history can hardly be characterized as definitional of the term “marker substance,” and cannot he used, in my view, as a basis to conclude that “marker substance” corresponds to an antigen, and not portions thereof.
“Where, as here, the written description and prosecution history fail to express a manifest exclusion or restriction limiting the claim term, and where the written description otherwise supports the broader interpretation, we are constrained to follow the language of the claims, and to give the claim term its full breadth of ordinary meaning as understood by persons skilled in the relevant art.” Brookhill-Wilk 1, LLC. v. Intuitive Surgical, Inc., 334 F.3d 1294, 1301-02 (Fed.Cir.2003) (internal quotations and citation omitted); see also ACTV, Inc. v. Walt Disney Co., 346 F.3d 1082, 1091 (Fed.Cir.2003); Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1328 (Fed.Cir.2002). From my review of the intrinsic evidence, the “marker substance,” as described by the specification and set forth in the claims, plainly embraces portions of an antigen, provided that they are inside the cell. Because transmembrane antigens generally have an element that extends into the intracellular region, I would submit that the intracellular portion of such an antigen plainly falls within the scope of “intracellular marker substance.”
Notably, the patentee clearly knew of and knew how to use the word “antigen,” as shown by its use of the term throughout the applications that led to the '559 and '744 patents. Evidently, however, the pat-entee chose not to use that term in the claims, instead choosing “marker substance.” Although the majority correctly observes that the patentee indicated that an antigen may be a marker substance, it cites to nothing in the intrinsic record that negates the indication by the specification and claims that “marker substance” may also correspond to only a portion of an antigen.
Appellees contend that even if appellants’ claim construction is correct, they do not literally infringe because no portion of the antigen to which their antibody responds, is located inside the cell. This question of infringement, either literal or under the doctrine of equivalents, is a disputed factual matter that should be left to the district court to resolve in the first instance. Given my view of the term “intracellular marker substance,” I would reverse the claim construction, vacate the summary judgment entirely, and remand for further findings as to infringement literally and, if necessary, under the doctrine of equivalents. Accordingly, I respectfully dissent-in-part and concur-in-part with the majority’s opinion.