GZMB and neoplasm: The authors showed that DNA methylation levels of signature genes are associated with T cell phenotypes: Tcf7, a naïve characteristic gene, was demethylated in TN, but highly methylated in TEM cells and tumor-infiltrating lymphocytes (TILs); Ifng and Gzmb, known as cytotoxic characteristic genes, were highly methylated in TN, but demethylated in TEM cells (Yang et al., 2019).