CD274 and acute lymphoblastic leukemia: Unlike the solid tumor-induced Erythroid cells (48, 49), both normal and ALL bone marrow Erythroid cells did not express either PDCD1 (PD-1) or CD274 (PD-L1) genes, which indicates a difference in the gene expression profile of immunoregulatory molecules between normal bone marrow Erythroid cells and their solid tumor-induced counterparts.