PDCD1 and neoplasm: The mechanisms of action of lenvatinib include (Figure 6): downregulating the expression of PD-1, CTLA-4, and TIM3 in T cells; blocking the binding of VEGFA and bFGF to their receptors, thereby inhibiting T-cell exhaustion (Deng et al., 2020); and destroying tumor cells, leading to the release of tumor antigens, which in turn promotes IFN-γ-mediated antigen presentation (Kato et al., 2019) and enhances the cytotoxicity of natural killer cells (Zhang et al., 2019).