definiens: shall mean, with respect to GDF-8, any GDF-8 Produc t, or any GDF-8 Derivative Product ( a ) all Patents covering inventi ons ( as such term is defined under United States Patent Law ) which ( i ) as of the Effective Date are Controlled by or during the term of this Agreement come into the Control of either Party, either alone or jointly ( including, without limitation, jointly with JHU pursuant to the 1994 Agreement or the 1999 Agre ement ) and ( ii ) are reasonably useful, necessary or required for the other Party and its Affiliates to manufacture, use and/or sell GDF-8 Licensed Products for use in the MetaMorphix Field or the GI Field, as applicable, and ( b ) all Patents coming into the Control of a Party during the term of this Agreement, which, but for the inclusion of such acquired Patents under this clause ( b ), would preve nt the other Party and its Affiliates from practici ng under one or more of the Patents included under cla use ( a ) above