In addition to Treg inhibition, myeloid-derived suppressor cells (MDSC) have been implicated in PI3Kδi-mediated therapeutic responses.10 In both Bim+/+ and Bim−/− leukemia-recipient animals, the frequency of splenic MDSC populations (CD11b+ Ly6CHigh Ly6GLow monocytic-MDSC (M-MDSC) or CD11b+ Ly6CLow Ly6GHigh polymorphonuclear-MDSC (PMN-MDSC)) were unaffected by PI3Kδi administration (Supplementary Figure 12). Here, ITGAM is linked to leukemia.