CD80 and B-cell chronic lymphocytic leukemia: Induction of the accessory molecule ICAM-1 (CD54), the co-stimulatory molecules B7.1 (CD80) and B7.2 (CD86), and the death receptor Apo1 (CD95) on B-CLL cells upon incubation with CD154+/gp350+ exosomes (Figure 2E) but not with exosomes from 293 cells provided an explanation for improved recognition by T lymphocytes.