IL2 and neoplasm: The immunostimulatory effects of LITs have been gradually elucidated, which include [19]: (1) promoting the release of tumor antigens; (2) modulating the expression of ICPs, including PD-1, PD-L1, CTLA-4, LAG-3, etc.; (3) producing immunomodulatory cytokines and chemokines, including INF-γ, IL-2, CXCL-9, etc.; and (4) facilitating the intratumoral infiltration of tumor-killing immune cells, including cytotoxic T cells, NK cells, and Th1 T cells.