Most studies focused on CD8+ T lymphocytes (Sato et al., 2005; Galon et al., 2006; Sharma et al., 2007; Mahmoud et al., 2011; Rahbar et al., 2015; Carstens et al., 2017), which can recognize and kill cancer cells with specific antigens (Martínez-Lostao et al., 2015). The gene discussed is CD8A; the disease is cancer.