It is also well-known that tumor-infiltrating CD8+ T lymphocytes confer a favorable prognosis in various types of cancers, including bladder (Sharma et al., 2007), colon (Ling et al., 2014), colorectal (Galon et al., 2006), esophageal (Gao et al., 2020), pancreatic (Carstens et al., 2017), breast (Mahmoud et al., 2011) and liver (Kondratiev et al., 2004) cancers. The gene discussed is CD8A; the disease is cancer.