CD8A and neoplasm: Regarding the correlation between TRM cells and ICB treatment efficacy, studies have reported that the number of CD8+TRM cells is correlated with the tumor microenvironment and the efficacy of immunotherapy in patients with NSCLC (23); the TRM cells from HBV-related HCC express higher levels of PD-1 are functionally more suppressive and exhausted than those from non-virus-related HCC and respond poorly to immune checkpoint blockade (24).