The presence of PD‐L1+ exosomes in plasma has been identified as a potential predictive biomarker for response to anti‐PD‐1 therapy.[36, 37] In our study, depletion of exosomal CMTM4 in tumor cells led to a notable reduction in PD‐L1 expression, enhanced macrophage‐mediated phagocytosis of tumor cells, and promoted increased infiltration of effector T cells into the peritoneal cavity of mice. Here, CD274 is linked to neoplasm.