 Though oncology was the top priority for OSI, research and development targeting type 2 diabetes and obesity was conducted through their U.K. subsidiary Prosidion Limited.OSI has also made a foray into the ophthalmology market through a marketing agreement with Pfizer over Macugen (Pegaptanib) for Age-related macular degeneration; however, acquisition of the firm Eyetech, meant to provide control over this product and diversify the company, was unsuccessful, ending in divestiture.In mid-2007, OSI's revenues were based primarily on proceeds from Tarceva sales (which are shared with Genentech and Hoffmann–La Roche) and royalty payments related to dipeptidyl-peptidase IV inhibitor intellectual property.