Reactivity of BM T cells from MM patients is inhibited upon coculture with myeloma cells. Cumulative mean ± standard error of the mean (SEM) numbers of IFN-γ–secreting, freshly isolated BM T cells from 11 MM patients (A) and mean values of individual results (B) from these patients with (black bars) or without (white bars) coculture with sorted CD138+ autologous (autol.) myeloma cells, as analyzed by short-term IFN-γ Elispot assay.