definiens: means all tangible materials in the possession and Control of [COMPANY] and/or itsAffiliate(s ) as of the Effective Date or thereafter during the Term that ( a ) are necessary or reasonably useful for theevaluation, Development, manufacture and/or Commercialization of Compounds and/or Products in the Field or(b ) otherwise embody [COMPANY] Know - How . [COMPANY] Materials shall include cell lines ( including Host Cell Lines, andresearch cell banks thereof ), DNA constructs and other materials necessary for the expression of Compounds, andtangible materials for use in assays necessary or reasonably useful for the characterization of Compounds . Subject toand to the extent as provided in Section 17.8, the use of in this definition shall exclude any Third Party thatbecomes an Affiliate due to a Change of Control Transaction involving [COMPANY] ( or any of its Affiliates ) and such ThirdParty