definiens: means any and all Know - How ( including without limitation ALNYLAM Collaboration Inventions ), which : ( a ) as of the Original Effective Date and/or during the Collaboration Term, is in the Control of ALNYLAM or its Affiliates, including without limitation, all Know - How of ALNYLAM 's scientific advisors and consultants which is Controlled by ALNYLAM or its Affiliates, and ( b ) is necessary or useful to MERCK for in vitro and/or in vivo target identification and/or target validation and/or for the Development, Manufacture or Commercialization of RNAi Therapeutic Products within the Therapeutic Collaboration, including, but not limited to, knowledge related to ( i ) the RNAi pathway and mechanism of action in mammalian cells, ( ii ) informatics approaches to optimal siRNA design for targeting specific genes and minimizing off - target effects, ( iii ) optimal RNA chemistry for siRNA in vivo stability and delivery, ( iv ) bio - analytical methods for measurement of pharmacokinetics and biodistribution of siRNAs, and ( v ) RNAi delivery methods