Since naïve T cells have an enormous TCR repertoire diversity capable of recognizing virtually any non-self antigens including pathogens and tumor neoantigens (de Greef et al., 2020; Qi et al., 2014), creating a high-quality naïve CD8 T cell population ready to give rise to potent long-lasting T cell responses would provide better protection against infections, enhance vaccine-induced immunity, and prevent cancer. This evidence concerns the gene CD8A and cancer.