PDCD1 and neoplasm: These data validate the functional role of stromal cells in the inflammatory CRC TME and suggests that targeting the PD-1/PD-L1 and/or SIRP-α/CD47 axis in macrophages, in addition to an activation stimulus, may enhance anti-tumor effector functions, such as macrophage-mediated phagocytosis as well as T cell-mediated anti-tumor immunity.19