P2RX7 and neoplasm: DAMPs that are exposed to a large number of dead tumor cell surfaces or released into the TME can be recognized by APCs surface receptors such as toll-like receptor-4 (TLR-4), calrectin receptor (CRTR), and purinergic receptor P2RX7 (20), thereby promoting the maturation and proliferation of APCs, and sequentially leading to the activation of cytotoxic lymphocytes.