CD274 and cancer: M2 macrophages also often exhibit surface molecules like PD-L1 which further contribute to their ability to suppress immune responses.105,106 Various studies have shown that disrupting the M2 macrophage pathway and guiding these cells toward an M1 phenotype can potentially improve the efficacy of ICIs.107 In addition, an imbalance marked by a lower ratio of adaptive immune responses to pro-tumorigenic signals within phagocytic myeloid cells has been associated with a lack of response to PD-L1 blockade therapy, particularly in cancer types such as urothelial cancer.108