For example, multiple epigenetic profiling studies in tumor infiltrating Tex cells demonstrated altered chromatin accessibility in thousands of differentially accessible regions, including decreases in chromatin accessibility of genes associated with effector T cell differentiation, such as IFNγ, TNFα, IL-2, KLRG1, and others, and increases in chromatin accessibility of genes associated with T cell exhaustion, such as PD-1, Tim3, LAG3, TIGIT, TOX, Tcf7, NFAT, and others (Sen et al., 2016; Abdel-Hakeem et al., 2021; Giles et al., 2022a; Belk et al., 2022). The gene discussed is PDCD1; the disease is neoplasm.