Elevated numbers of activated CD8 + T cells within the TME are associated with positive outcomes among patients with breast cancer, colorectal cancer, renal cancer, and melanoma (Clemente et al., 1996; Tosolini et al., 2011; Gu-Trantien et al., 2013; Bohner et al., 2019; Ye et al., 2019). The gene discussed is CD8A; the disease is colorectal cancer.