CD8A and colorectal carcinoma: Studies have shown that compared to ICIs alone, the combination of ICIs and natural products can exert synergistic effects on CRC by promoting antigen presentation, enhancing CD8+ T cell cytotoxic activity, increasing T cell infiltration and so on (Liu et al., 2020b; Liu et al., 2020c; Lee et al., 2021; Xu et al., 2021).