CD8A and neoplasm: The migration of TAMs and the metastasis of tumor cells can be promoted by the interaction between tumor cells and immune cells via TNFSF9 and its receptor TNFRSF9.[17] Wu and colleagues reported that in pancreatic cancer, TNFSF9 can promote M2 polarization of TAMs by activating the AKT signaling pathway, which in turn weakens the tumor-killing activity of CD8 + T cells in the TME and contributes to the metastasis of pancreatic cancer.[18]