FASLG and leukemia: In support of this idea, the present study newly defines that resting human peripheral blood B cells: 1) express multiple cytotoxic transmembrane TNFSF ligands such as TNF, FasL, LT-α1β2 and/or TRAIL; and 2) mediate a powerful innate apoptotic killing of virtually all types of leukemia and carcinoma cells and normal proliferating endothelial cells and fibroblasts through simultaneous engagement of these ligands.