As with osteocalcin, concentrations of COMP were also indistinguishable between the three experimental groups: 413.2 (339.9) U/L in the asymptomatic organ donor group, 490.2 (207.5) U/L in the OA group and 507.3 (352.9) U/L in the RA group (Table 2). The gene discussed is COMP; the disease is rheumatoid arthritis.