CD8A and neoplasm: Due to the high enrichment of infiltrating regulatory T cells (Tregs) and exhausted CD8+ T cells in HCC, the regulatory imbalance in the tumor immune microenvironment has an important impact on the initiation, progression and resistance of HCC, which possesses features of immunosuppressive disease (Zheng et al., 2017; Ringelhan et al., 2018; Ruf et al., 2020).