The district court concluded that the U.S. Patent and Trademark Office “improperly revived” U.S. Patent No. 7,056,-215 after it was abandoned during prosecution, and therefore held it (and the continuation patent that followed it) invalid on summary judgment. We conclude that “improper revival” is not a cognizable defense in an action involving the validity or infringement of a patent. Thus, we reverse the district court’s grant of summary judgment and remand for proceedings consistent with this opinion.
I. BACKGROUND
Aristocrat Technologies Australia Pty, Ltd. and Aristocrat Technologies, Inc. (collectively, “Aristocrat”) compete with International Game Technology and IGT (collectively, “IGT”) in the market for electronic gaming machines. Aristocrat is the assignee of U.S. Patent Nos. 7,056,215 (“the '215 patent”) and 7,108,603 (“the '603 patent”), both of which relate to a “slot machine game and system with improved jackpot feature.” Prosecution of these patents began in Australia, when, starting on July 8, 1997, Aristocrat filed two provisional patent applications directed to the inventions embodied in the patents-in-suit. One year later, Aristocrat filed a Patent Cooperation Treaty application (“the PCT application”) in Australia, claiming priority to the previously filed provisional applications. The PCT application was subsequently published. Pursuant to 35 U.S.C. § 371 and 37 C.F.R. § 1.495, Aristocrat was required to. pay the fee for the U.S. national stage of the PCT application by January 10, 2000— thirty months after the filing date of the first Australian provisional application.
The U.S. Patent and Trademark Office (“PTO”) did not receive Aristocrat’s national filing fee until January 11, 2000— one day late. The PTO consequently mailed a noticе of abandonment to Aristocrat, which stated, among other things, that Aristocrat “may wish to consider filing a petition to the Commissioner under 37 CFR 1.137(a) or (b) requesting that the application be revived.” J.A. at 642. In lieu of filing a petition to revive the abandoned application, Aristocrat responded by fifing a Petition to Correct the Date-In-that is, to correct the date on which the PTO received its national fifing fee. The PTO denied the petition without prejudice, after Aristocrat failed to provide sufficient evidence to corroborate the date the fifing fee was mailed. It is unclear when Aristocrat received the PTO’s denial, 1 but it later filed a petition to revive the '215 patent application under 37 C.F.R. § 1.137(b), claiming that the delay in paying the na *660 tional stage filing fee was “unintentional.” Id. at 660-61. The PTO granted the petition to revive on September 3, 2002, after conсluding that “[a]ll of the requirements of 37 CFR 1.137(b) ha[d] been met.” Id. at 687. Following the PTO’s revival, Aristocrat resumed prosecution of the '215 patent application, and later filed the '603 patent application as a continuation of the '215 patent application. The '215 patent issued on June 6, 2006, and the '603 patent issued on September 19, 2006.
In June 2006, Aristocrat filed suit against IGT for infringement of the '215 patent in the United States District Court fоr the Northern District of California. Aristocrat amended its complaint to assert infringement of the '603 patent when that patent issued. IGT answered and subsequently moved for summary judgment of invalidity. It argued that the '215 patent was invalid because, after it was abandoned, Aristocrat was required to show that its delay was “unavoidable” in order to revive the application, not merely that its delay was “unintentional.” Thus, according to IGT, the PTO “improperly revived” the '215 patent application by requiring Aristocrat only to show “unintentional delay.” IGT also argued that the '603 patent was invalid, contending that since the '215 patent application was not lawfully revived, it constituted prior art to, and thus anticipated, the '603 patent under 35 U.S.C. § 102(b).
The district court granted IGT’s motion. It first concluded that the Patent Act permitted revival of an abandoned patеnt application only upon a showing of “unavoidable delay.”
Aristocrat Techs. Austl. Pty, Ltd. v. Int’l Game Tech.,
Aristocrat timely appealed. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
II. DISCUSSION
A. Standard of Review
Statutory interpretation is a question of law, which we review de novo.
Imazio Nursery, Inc. v. Dania Greenhouses,
B. Analysis
1. The '215 Patent
The threshold issue in this appeal is whether “improper revival” may be *661 raised as an invalidity defense in an action involving the infringement or validity of a patent. The district court, relying on 35 U.S.C. §§ 282(2) and (4), decided that question affirmatively. The district court also found that the APA provided a separate basis uрon which to review the PTO’s revival of the '215 patent. We conclude that “improper revival” may not be raised as a defense in an action involving the validity or infringement of a patent. 2
Section 282 of title 35 provides a catalog of defenses available in an action involving the validity or infringement of a patent:
(1) Noninfringement, absence of liability for infringement or unenforceability,
(2) Invalidity of the patеnt or any claim in suit on any ground specified in part II of this title as a condition for patentability,
(3) Invalidity of the patent or any claim in suit for failure to comply with any requirement of sections 112 or 251 of this title,
(4) Any other fact or act made a defense by this title.
The first and third enumerated categories are not asserted by IGT as bases for its invalidity defense. At issue are the second and fourth. We discuss each in turn.
Section 282(2) authorizes an invalidity defense based “on any ground specified in part II of this title as a condition for patentability.” A defense falling under this section thus has two prerequisites: it must fall within part II of title 35 and it must be a “condition for patentability.” The district court determined that “[b]e-cause Section 133’s six-month deadline for prosecuting an application is specified within part II of Title 35, it necessarily provides an available defense where a pat-entee has abandoned, and failed to lawfully revive, a patent application.”
Aristocrat,
It has long been understood that the Patent Act sets out the conditions for pat-entability in three sections: sections 101, 102, and 103.
See Graham v. John Deere,
While there are most certainly other factors that bear on the validity or
*662
the enforceability of a patent, utility and eligibility, novelty, and nonobviousness are the only so-called conditions for patentability. For example, section 112 unquestionably provides certain additional requirements for a patent to be valid, one of which, for instance, is that the patented invention be enabled by the specification. 35 U.S.C. § 112, ¶ 1. But the requirements in section 112 are not conditions for pat-entability; they are merely requirements for obtaining а valid patent. Indeed, section 282 itself draws a distinction between invalidity based “on any ground specified in part II of this title as a condition for patentability,” 35 U.S.C. § 282(2), and invalidity “for failure to comply with any requirement of sections 112 or 251,” 35 U.S.C. § 282(3).
See Sextant Avionique, S.A. v. Analog Devices, Inc.,
The district court also found that improper revival was an available defense under section 282(4), the catch-all provision of section 282, which provides a defense for “[a]ny other fact or act made a defense by” title 35. After reciting this statutory language, the district court concluded, “A fortiori, Section 282(4) must therefore incorporate Section 133 and 371(d).”
Aristocrat,
The salient question, then, is whether improper revival is “made a defense” by title 35. We think that it is not. Congress made it clear in various provisions of the statute when it intended to create a defense of invalidity or noninfringement, but indicated no such intention in the statutes pertaining to revival of abandoned applications. For example, 35 U.S.C. § 273 is entitled “Defense to infringement based on earliest inventor” and exрressly provides that the provision “shall be a defense to an action for infringement.” Similarly, 35 U.S.C. § 185 states that a patent issued to a person who has violated the secrecy provisions of section 184 “shall be invalid,” except under certain circumstances. Section 272 of title 35 provides that the temporary presence of a patented invention in the United States, if used exclusively for the needs of a vessel, aircraft, or vehicle, “shall not constitute in *663 fringement.” The list goes on. What is important to note is simply that sections 133 and 371, relied upon by IGT, provide none of the signals that Congress has given in other circumstances to indicate that these sections provide a defense to an accused infringer. Rather, these provisions merely spell out under what circumstances a patent applicаtion is deemed abandoned during prosecution and under what circumstances it may be revived. See 35 U.S.C. § 133 (“Upon failure of the applicant to prosecute the application within six months ..., the application shall be regarded as abandoned .... ”); id. § 371 (“Failure to comply with these requirements shall be regarded as abandonment of the application”) Because the proper revival of an аbandoned application is neither a fact or act made a defense by title 35 nor a ground specified in part II of title 35 as a condition for patentability, we hold that improper revival may not be asserted as a defense in an action involving the validity or infringement of a patent.
Our conclusion that improper revival is not a defense comports with the approach we took in
Magnivision, Inc. v. Bonneau Co.,
We acknowledge that section 282 is not the only source of defenses in the Patent Act.
See Quantum Corp. v. Rodime, PLC,
If the only penalty for violating section 305 is a remand to the PTO to have the reexamined claims narrowed to be commensurate in scope with what the applicant was only entitled to in thе first place, then applicants will have an incentive to attempt to broaden their claims during reexamination, and, if successful, be able to enforce these broadened claims against their competitors.... The likelihood that improperly broadened claims will be held invalid will discourage applicants from attempting to broaden their claims during reexamination.
Id. (internal citations omitted). 5
The analysis and result in
Quantum
are inappositе to this appeal. Even if we assume that the Patent Act permits revival of an application only upon a showing of unavoidable delay, a question that we expressly decline to reach in this appeal, none of the considerations that led us to the rule enunciated in
Quantum
compels a similar result here. A primary concern in
Quantum
was that failure to impose invalidity for violation of the statute would encourage noncompliance. That concern is simply not present here, as we discern no legitimate incentive for a patent applicant to intentionally abandon its application, much less to attempt to persuade the PTO to improperly revive it. Because patents filed after enactment of the Uruguay Round Agreements Act, like the patents at issue here, generally have a term that runs twenty years from the filing date (insteаd of seventeen years from issue),
cf. Merck & Co. v. Hi-Tech Pharmacal Co.,
We have considered IGT’s arguments attempting to bolster the district court’s decision under the APA, but find them unpersuasive. Under the circumstances of this case, the APA provides no relief to IGT.
2. The '60S Patent
The district court’s conclusion with respect to the '215 patent ordained the fate of thе '603 patent. Once it was determined that the '215 patent application was improperly revived, the '603 patent application, which was filed as a continuation application of the '215 patent application, was no longer able to claim priority to that
*665
application’s effective filing date. As a result, the '215 patent application became prior art to the '603 рatent. On this basis, the district court granted summary judgment that “the '603 Patent is necessarily invalid [under 35 U.S.C. § 102(b)] because it was described in the published '215 PCT Application more than one year prior to its date of application.”
Aristocrat,
III. CONCLUSION
For the reasons discussed above, we reverse the district court’s grant of summary judgment and remand for proceedings consistent with this opinion.
Notes
. The parties dispute when Aristocrаt received notice of the denial. Because this dispute is unimportant to our analysis, we do not discuss it further here.
. Because it is on this basis that we decide the appeal, we do not reach the parties' alternative arguments, including those relating to whether the Patent Act permits revival for "unintentional'' — as opposed to "unavoidable” — delay.
. Although the Supreme Court in Graham referred only to the utility requirement aspeсt of section 101, as we often do, it is beyond question that section 101's other requirement, that the invention be directed to patentable subject matter, is also a condition for patenta-bility.
. We take this opportunity to point out that “prosecution irregularities” is distinct from "prosecution laches.” Prosecution laches stems not from any procedural lapse or irregularity during prosecution, but rather from an abuse of statutory provisions that results, as a matter of equity, in "an unreasonable and unexplained delay in prosecution.”
Symbol Techs., Inc. v. Lemelson Med., Educ. & Research Found.,
. We also point out that since section 282(3) provides an invalidity defense for failure to comply with section 251, which in turn prohibits the broadening of claims in
reissue
applications after two years, 35 U.S.C. § 251 ¶ 4, the result in
Quantum
mirrors the statutory framework set
out
for the analogous reissue context.
Cf. Quantum,
