TCF7 and neoplasm: Functionally, while TCF1– terminally exhausted tumor-infiltrating CD8 lymphocytes (TILs) expressed more interferon-γ (IFN-γ) and granzyme B, TCF1+ stem-like TILs were more polyfunctional, as shown by co-producing IFN-γ, tumor necrosis factor α (TNFα) and IL-2 [71,78].