Studies in models of chronic viral infections indicated TCF1+ CD8+ T cells can be hyper proliferative upon anti-PD-1 therapy and is critical for viral control and limiting tumor progression (He et al., 2016; Im et al., 2016; Leong et al., 2016; Wu et al., 2016; Kurtulus et al., 2019; Siddiqui et al., 2019). This evidence concerns the gene CD8A and neoplasm.