definiens: means any challenge to the patentability or valid ity of a Patent by : ( a ) filing a declaratory judgment action in which any s uch Patent is alleged to be invalid or unenforceabl e ; ( b ) citing prior art pursuant to 35 U.S.C. § 122 or § 301, filin g a request for re - examination of any such Patent p ursuant to 35 U.S.C. § 302 or § 311, filing a petition to reques t an inter partes review of any such Patent pursuan t to 35 U.S.C. § 311, or filing a petition to request a post -grant review of any such Patent pursuant to 35 U.S .C. § 321 ; or ( c ) filing or commencing any re - examination, opposi tion, cancellation, nullity or similar proceeding a gainst any such Patent in any country, in each case of the for egoing ( ( a ), ( b ), and ( c ) ) in any judicial or admin istrative proceeding in the United States, including before t he U.S. Patent and Trademark Office ; provided, howe ver, that it shall not be deemed a hereunder for a Party to take any of the foregoing actions with r egard to any such Patent in response to any claim, action - 2 – [ * * * ] Confidential Information, indicated by [ * * * ], has been omitted by this filing and filed separate ly with the Securities and Exchange Commission