As an upstream regulator of PD-L1, CCL22 and DGKζ expression, miR-34a was identified as an important regulator of immune response in cancer.31, 85, 86 MiR-34a overexpression reversed chemotherapeutic agent-induced PD-L1 expression, reduced PD-L1 specific T cell apoptosis and inhibited Treg recruitment in p53-defective models.31, 86. This evidence concerns the gene CD274 and cancer.