Proliferative activity of cytogenetically defined myeloma cells.

Five patients with a 13q14 deletion determined by FISH analysis with a rb-1 specific probe were studied for BrdU incorporation. Both rb-1–deleted and rb-1–nondeleted cells were found to be proliferative. Proliferation of these multiple myeloma (MM) cells was greater than that of MM cells from 5 patients with normal chromosome 13q14 on FISH analysis.