For instance, because the expression of PD-1 on T cells and PD-L1 on APCs facilitated increased Tregs and decreased CTL functions, PD-1/PD-L1 blockade with anti-PD-L1 monoclonal antibody decreased the infiltrating number of Tregs and increased the number and function of tumor reacting CTLs in an AML mouse model (167). This evidence concerns the gene CD274 and acute myeloid leukemia.