TP53 and B-cell chronic lymphocytic leukemia: To show that the activity of Ulocuplumab (BMS-936564) was p53 independent, we incubated leukemia cells derived from either TP53wt or TP53mut /Del(17p) CLL patients and Ramos (TP53mut), and compared the level of apoptosis induced by F-ara-A, which is known to be a p53 dependent chemotherapy agent.