definiens: means, on a country -by - country basis, any suspected or threatened infringement by a Third Party of any [COMPANY] Patent, [COMPANY] O wned Patent or Jointly Owned Patent ( ), where ( a ) any such alleged or threatened Infringement is on account of a Third Party ’s manufacture, use, import, offer for sale or sale of a VISTA Antagonist in the Field ; ( b ) a Third Party files any certification in the United States under 21 U.S.C. § 355(b)(2 ) or 21 U.S.C. § 355(j)(2 ) or similar provisions in other jurisdictions in connection with an abbreviated biological product application, or any foreign equivalent thereof, or other BLA, in each case, for a VISTA Antagonist, wherein a Product is the reference product ( a ) ; or ( c ) any declaratory judgment action filed by a Third Party that is developing, manufacturing or commercializing Products in the Field alleging the invalidit y, unenforceability or non -infringement of any of the [COMPANY] Patents, [COMPANY] Owned Patents or Jointly Owned Patents