definiens: ) which are selective for Estrogen Receptor ( ) ( alpha ) ( ) in U2OS cells ( the as defined in Section 1.16 ) ; WHEREAS, [COMPANY] and its affiliates engaged in the research, development, marketing, manufacture and distribution of pharmaceutical compounds useful in treating or preventing human diseases and conditions ; and WHEREAS, the Parties desire to engage in a joint research effort to identify or discover, on the basis of [COMPANY] 's lead and library compounds, SERMs which are Er(alpha)Selective in U2OS cells ( including, without limitation, compounds in the SP500263 Series ( as defined below ), as well as analogs t hereof made by [COMPANY] prior to the Effective Date as part of its internal research program in the Oncology Fild ( as defined below ) to develop pharmaceutical products from such compounds for the treatment, prevention and diagnosis of osteoporosis and for other indications as described herein