CD38 and acute myeloid leukemia: Moreover, the apoptotic cell fraction (annexin V+ 7-AAD+) of CD34+CD38− primary AML LSCs remarkably increased upon cotreatment with GSK2606414 and BIX-01294 [20.74 ± 3.88% for BIX-01294 alone and 59.36 ± 6.92% for BIX-01294 plus GSK2606414; P = 0.0004; Fig. 3a (right panel) and 3B].