Di Cesare and colleagues were able to resolve a major reduction-sensitive 150 KD COMP fragment, which may include the pentamerizing domain and some portion of the type-2 repeats and non-reduction-sensitive 67 to 94 kDa fragments which must be C-terminal fragments present in cartilage extracts of patients with RA and osteoarthritis (OA) [36]. The gene discussed is COMP; the disease is osteoarthritis.