Each Party shall promptly provide the other Party with written notice reasonably detailing (i) any known or alleged infringement by a Third Party of Arising IP, Joint Arising IP and Calithera IP , including any “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 of any declaratory judgment, opposition, or similar action by a alleging the invalidity, unenforceability or non-infringement of any such Intellectual Property Rights (collectively “ Third Party Infringement ”) and (ii) any allegation by a Third Party that Intellectual Property Rights owned by it is infringed, misappropriated or violated by the manufacture, research, Development or Commercialization of any Licensed Compound or Licensed Product in the Hematology/Oncology Field of which it becomes aware (“ Defense Action ”).