CD274 and acute lymphoblastic leukemia: To elucidate the underlying immune evasion mechanisms in ALL leukemic cells, the effects of Bcl-2 and BTK inhibitors were assessed on the mRNA expression profile of immune checkpoint ligands PD-L1, CD200, CD155, Gal-9, and CD47, as well as the anti-inflammatory cytokine TGF-β, in leukemic cells.