PCR amplification showing rearrangement of third framework region in the V_H region of heavy chain Ig gene in the lymphoma cells of all 13 cases, HHV-8 genome in 4 cases (lanes 3 and 4, AIDS patients; lanes 7 and 9, non-AIDS patients), and EBV genome in 1 case (lane 4, AIDS with lymphoma involving the orbit and eye). Lanes 1 through 13, cases no. 1 through 13, respectively; lane 14, negative control; lane 15, positive control.