Inhibition of PKCδ resulted in the induction of caspase-dependent apoptosis, and reduction in expression of the anti-apoptotic factors Mcl-1 and X-linked inhibitor of apoptosis (XIAP) [47], suggesting that in addition to PKCβII, PKCδ may play a key role in regulating CLL cell survival. The gene discussed is MCL1; the disease is B-cell chronic lymphocytic leukemia.