Each Party shall immediately provide the other Party with written notice reasonably detailing any (i) known or alleged infringement of any Agios Patents, Celgene Patents, Celgene Collaboration Patents, Agios Co-Co Collaboration Patents or Joint Collaboration Patents, or known or alleged misappropriation of any Agios Know-How, Celgene Know-How, Celgene Collaboration Know-How, Agios Co-Co Collaboration Know-How or Joint Collaboration Know-How, by a Third Party, (ii) “patent certification” filed 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, and (iii) any declaratory judgment, opposition, or similar action alleging the invalidity, unenforceability or non-infringement of any such intellectual property rights (collectively “ Third Party Infringement ”).