concurring-in-part and dissenting-in-part.
While I concur in the majority’s construction of the claim limitations “regulatory sequence” and “stably overexpressed,” I must respectfully dissent from its conclusion regarding the construction of the “chromosomally integrated” limitation. In my view, the restriction of the scope of this limitation to require the introduction into a host cell of “exogenous sequences encoding ¥-Gal A,” Genzyme, slip op. at 1105, unadvisedly reads limitations from the specification into the claims. I can discern no proper basis to do so and would give the “chromosomally integrated” limitation the full scope of its ordinary and customary meaning.
I. CLAIM CONSTRUCTION
A. Ordinary and Customary Meaning
It is well settled in our jurisprudence that claim terms are to be given their ordinary and customary meaning to one of skill in the relevant art. Johnson Worldwide Assocs., Inc. v. Zebco Corp., 175 F.3d 985, 989 (Fed.Cir.1999). Determining the ordinary and customary meaning of the terms of the claims is the first step in claim construction, and consultation of the written description and prosecution history before attempting to ascertain the ordinary and customary meaning of the language of the claims is premature. Tex. Digital Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193, 1204 (Fed.Cir.2002). Where the patentee’s choice of a claim term “de-privets] the claim of clarity,’ ” CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1367 (Fed.Cir.2002), however, the court must “resort to the other intrinsic evidence,” id., to determine the meaning of the claim terms.
In my view, the majority hastens too quickly past the fundamental step of determining the ordinary and customary meaning of “chromosomally integrated.” It relies on a single definition of “integration,” defined in the context of “viral or another DNA sequence,” to import the concept of a “host genome.” Genzyme, slip op. at 1098; Benjamin Lewin, Genes IV 812 (1990). In light of this imported concept of a “host cell,” the majority perceives ambiguity as to “whether one of skill in the art at the time of the invention would understand the exogenous sequences to come from outside the host cell, i.e., a vector, or from within the host cell but outside the critical chromosome, i.e., a transposable element.”4 *1107Genzyme, slip op. at 1098. It then turns to the specification to resolve this perceived ambiguity.
With all due respect to my colleagues, there is no ambiguity here to be resolved. The majority opinion establishes that the term “chromosomally integrated” could be used in reference to the incorporation into a chromosome of either endogenous or exogenous DNA, that is to say, DNA sequences that have their origin either inside or outside the cell to which the chromosome is native. The ordinary and customary meaning of the term broadly encompasses both possibilities. It is incorrect to perceive a claim term as ambiguous merely because of its breadth and to require that the term be redefined to encompass only a portion of its ordinary meaning in the name of clarity.
Technical treatises publicly available at the time a patent is issued may be consulted as “reliable sources of information that would have been attributed to the terms of the claims by those of skill in the art.” Tex. Digital Sys., 308 F.3d at 1202-03. See also Inverness Med. Switz. GmbH v. Princeton Biomeditech Corp., 309 F.3d 1365, 1370 (Fed.Cir.2002) (‘We may look, therefore, to the dictionary definition of the claim term mobility as of the date the patents issued.”). A review of the relevant technical treatises contemporaneous with the issuance of the '804 patent shows that “chromosomally integrated” had a broad meaning, encompassing the integration of both exogenous and endogenous DNA. The Genes IV text that the majority cites uses the term “integrated” to describe both the incorporation of viral DNA of extracellular origin, Genes IV 674 (1990) (“One or more [viral] DNA copies become integrated into the host genome.”), and the transposition of yeast transposable elements from one site to another within the same genome, id. at 681 (describing yeast Ty transposa-ble elements as subject to “reverse transcription and integration”). Transposable elements, such as retroposons, were understood at the time to be a part of an organism’s own genome. Id. at 672 (“[W]e think of retroposons as genomic (duplex DNA) sequences that occasionally transpose within a genome; they do not migrate between cells.”). Another contemporaneous leading text similarly describes both viral DNA and transposable element DNA as integrating into the chromosome. Bruce Alberts et al., Molecular Biology of the Cell 255 (1989) (“[T]he DNA circle [of the transposable element] integrates into a randomly selected site on the chromosome.”) The term “chromosomally integrated” was thus commonly understood by those of skill in the art at the time to refer to the incorporation into a chromosome of DNA that either came from another site in the same genome or from outside the cell. This is the ordinary and customary meaning of the claim term.
B.The Intrinsic Record
The next step in the claim construction process in this case, as in every case, is to examine the intrinsic evidence, comprising the claims, the written description, and the prosecution history if in evidence, to determine whether the patentee has rebutted the presumption that “chromosomally integrated” has its ordinary and customary meaning. See Brookhill-Wilk 1, LLC v. *1108Intuitive Surgical, Inc., 334 F.3d 1294, 1298 (Fed.Cir.2003); Tex. Digital Sys., 308 F.3d at 1204. A patentee may rebut this presumption by “defin[ing] claim terminology in a manner inconsistent with its ordinary meaning,” Biovail Corp. Int’l v. Andrx Pharms., Inc., 239 F.3d 1297, 1301 (Fed.Cir.2001), or by disclaiming a particular interpretation of a claim term during prosecution, Biodex Corp. v. Loredan Biomedical, Inc., 946 F.2d 850, 863 (Fed.Cir.1991). I find no redefinition of the claim term in the intrinsic evidence, nor do I discern any disclaimer of coverage of the integration of endogenous DNA.
The word “integrated” or “integration” appears nine times in the sixty-page '804 written description. None of these instances on its own amounts to a “special definition ... clearly stated in the patent specification.” Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996). The majority correctly notes that “the applicant consistently uses the term ‘integrated’ to refer to a foreign gene inserted into a host cell chromosome.” Genzyme, slip op. at 1099. However, this use of “integrated” is not “inconsistent with [its] ordinary meaning,” Vitronics Corp., 90 F.3d at 1582, and cannot therefore be used to show that the patentee has redefined the term “with reasonable clarity, deliberateness, and precision,” In re Paulsen, 30 F.3d 1475, 1480 (Fed.Cir.1994). As the majority demonstrates, the ordinary and customary meaning of “integrated” embraces the incorporation of both exogenous and endogenous DNA. It is immaterial to the proper construction of “integrated” that the embodiments consistently employ exogenous DNA. Absent a redefinition or disclaimer relating to a claim term, consistent use in the written description of a term in a narrower meaning cannot trump a broader ordinary and customary meaning of the term as used in a claim. Were it otherwise, the scope of claim terms would regularly be limited to the embodiments disclosed in the specification. But it is the claim language, not the embodiments, which control. See Renishaw PLC v. Marposs Societa’ per Azioni, 158 F.3d 1243, 1248 (Fed.Cir.1998) ([T]he claims define the scope of the right to exclude; the claim construction inquiry, therefore, begins and ends in all cases with the actual words of the claim.).
The majority also cites the “Summary of the Invention” section, where “the present invention” is said to involve “host cell expression systems,” and the abstract, which refers to “engineered host cells.” '804 patent, col. 6, 11 22-25; Abstract. The majority contends that the term “host cell” necessarily implies the introduction of exogenous genetic material, and this amounts to a “definition of the invention.” Gen-zyme, • slip op. at 1099-1100. In other words, the majority sees a redefinition of the claim term “chromosomally integrated” in the use in the specification of a term, “host cell,” that appears nowhere in the claims. In my view, the majority roams too far afield in search of a redefinition of the claim term. ' It is clear from our precedent that any redefinition must focus on the term actually employed in the claims. See Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1324 (Fed.Cir.2002) (“The claim language defines the bounds of claim scope.”); Interactive Gift Express, Inc. v. Compuserve Inc., 256 F.3d 1823, 1331 (Fed.Cir.2001) (“In construing claims, the analytical focus must begin and remain centered on the language of the claims themselves, for it is that language that the patentee chose to use to ‘particularly point[ ] out and distinctly claim[ ] the subject matter which the patentee regards as his invention.’ ”); Thermalloy, Inc. v. Aavid Eng’g, Inc., 121 F.3d 691, 693 (Fed.Cir.1997) (“[throughout the interpretation *1109process, the focus remains on the meaning of claim language.”).
Like the written description, nothing in the prosecution history limits or redefines the scope or meaning of “chromosomally integrated.” The majority stresses the fact that “during prosecution, the applicant agreed that the pending claims required a recombinant vector encoding a-Gal A.” Genzyme, slip op. at 1101. However, this was predicated on the fact that the set of claims then pending explicitly required the use of a recombinant vector. The Examiner made clear that a deposit of the vector was required because the vector was present in the claims:
Since the veetor(s) is/are essential to the claimed invention it must be obtainable by a repeatable method set forth in the specification or otherwise be readily available to the public. If the vector(s) is/are not so obtainable or available, the requirements of 35 USC 112 may be satisfied by deposits) of the vector(s).
As the majority notes, the claims were later amended to remove the term “recombinant vector,” and the issued claims do not contain such a limitation.
Despite the removal of that limitation, however, the majority maintains that the deposited vector sequence remained necessary to the claimed invention, and this mandates a restriction of the scope of “chromosomally integrated.” I cannot agree. The deposit of the recombinant vector was required by the Examiner to establish enablement of then-pending claims that explicitly required its use. When the use of a recombinant vector was eliminated from the claims, the predicate for the Examiner’s deposition requirement evaporated. There is no reason to conclude in this case that an action taken as a result of the presence of a specific term in the claims should continue to bind the patentee when that term is removed during prosecution and does not appear in the issued claims. See Smith v. Snow, 294 U.S. 1, 16, 55 S.Ct. 279, 79 L.Ed. 721 (1935) (“It is of no moment that in the course of the proceedings in the Patent Office the rejection of narrow claims was followed by the allowance of the broader claim 1.”); United States v. Telectronics, Inc., 857 F.2d 778, 783 (Fed.Cir.1988) (The arguments emphasizing the use of a skin electrode, which were made at the time the application claims explicitly contained such a limitation, cannot furnish a basis for restricting issued claim 1, which lacks any such limitation.); Kistler Instrumente AG. v. United States, 224 Ct.Cl. 370, 628 F.2d 1303, 1308 (1980) ([Defendant's insistance [sic] upon this court’s reading back into the claims limitations which were originally there and were removed during prosecution of the application through the Patent Office cannot be permitted.).
The majority doubts, however, whether the removal of the recombinant vector limitation from the issued claims actually represented a broadening of the claims. Given that the amendment occurred at a late stage of prosecution, the majority states that if it were in fact broadening, the amendment would have been a violation of 37 C.F.R. 1.116(b), because the patentee made no showing of good and sufficient reasons why [it was] necessary and [was] not earlier presented. 37 C.F.R. 1.116(b) (1992). A decision restricting the scope of an otherwise unambiguous claim term based on an applicants presumed noncompliance with a procedural rule of the PTO strikes me as ill-founded. See Dethmers Mfg. Co., Inc. v. Automatic Equip. Mfg. Co., 293 F.3d 1364, 1366 (Fed.Cir.2002) (Linn, J., dissenting from the order denying rehearing en banc) ([0]nee a patent issues, non-compliance with a procedural rule administered by the PTO within the scope of the agency’s statutory authority *1110and found, by virtue of the grant of the patent, to have been satisfied during prosecution is, in and of itself, of no consequence.).
The majority also relies on arguments distinguishing certain prior art references to establish that the patentee “expressly confined the invention to production of proteins by introducing vectors into a mammalian host cell.” Genzyme, slip op. at 1102-1103. To establish a disclaimer or disavowal of claim scope, of course, a pat-entee must use “words or expressions of manifest exclusion or restriction, representing a clear disavowal of claim scope.” Tex. Digital Sys., 308 F.3d at 1204. The majority finds such a manifest exclusion of the use of a cell’s own endogenous DNA in the patentee’s assertions that the claimed invention was capable of recovering “recombinant protein,” and that such “hetero-logously expressed recombinant proteins” are difficult to purify. Genzyme, slip op. at 1101-1102. The patentee also referred to the claimed invention’s use of “an engineered mammalian cell system.” Id., slip op. at 1102-1103. I see no clear disavowal of the use of endogenous DNA in these remarks. Neither Tsuji nor Bishop employed endogenous DNA. The essence of the patentee’s argument was that, while the prior art employed exogenous DNA to achieve a low level of transient expression, the claimed invention was “the first demonstration of the stable, overexpression, selective secretion, and subsequent isolation of a lysosomal enzyme in a recombinant mammalian cell system.” Whether the prior art references integrated the cell’s own DNA into a different chromosomal site was simply not at issue.
II. ENABLEMENT
The majority notes that “the record would appear to raise questions of enablement,” although it also states that “this court need not examine enablement to properly define the claim term ‘chromo-somally integrated’ in view of the specification and prosecution history.” Genzyme, slip op. at 1104. To the extent that en-ablement concerns underlie the majority’s narrowing of the scope of “chromosomally integrated,” however, I suggest that such issues are not yet ripe for consideration. The district court has not yet addressed validity, and the parties did not brief the issue on appeal. Although this court has stated that claims should be interpreted so as to preserve their validity whenever reasonably possible, Modine Mfg. Co. v. United States Int’l Trade Comm’n, 75 F.3d 1545, 1557 (Fed.Cir.1996), it is wrong to allow enablement issues that have not yet been fully ventilated by the parties and the district court to influence a claim construction determination. I agree that all validity concerns should be left for another day.
. The majority’s claim construction analysis frames the question as whether "chromosom*1107ally integrated” can be construed to "cover a gene activation technique in which only a promoter sequence is inserted into a human host cell in order to activate the ct-Gal A gene already present in the host cell,” Genzyme, slip op. at 4, which is a description of TKT’s allegedly infringing technique. I believe the question is misdirected. Our precedent informs that "claims [should] not be construed by reference to the accused device.” Neo-Magic Corp. v. Trident Microsys., Inc., 287 F.3d 1062, 1074 (Fed.Cir.2002).