Expression ofmdm2by synovial cells using RT-PCR. Synovial tissue was isolated as described for Figure 3. RNA was used in RT-PCR with primers for mdm2 and GAPDH. RNA from tissue from the right (R, lanes 1 and 3) and left (L, lanes 2 and 4) knee joints after one (lanes 1 and 2) or 2 (lanes 3 and 4) episodes of hemarthrosis are shown. Similar results were obtained when tissue from day 3 or day 10 was analyzed. This experiment was repeated twice with similar results.