Absence of bcl-2 rearrangements in PBL, (6% polyacrylamide gel, staining with ethidium bromide). Case no. 1, tumor of patient no. 12; case no. 2, tumor of patient no. 15; case no. 3, tumor of patient no. 9; negative control, DNA extracted from a tonsil; positive controls, 2 cases of follicle center lymphomas.