IL4 and skin basal cell carcinoma: In patients affected by BCC, a more indolent and less aggressive form of skin cancer, tumor-infiltrating lymphocytes (TILs) express both type 1, i.e., IL-2 and IFNγ, and type 2, i.e., IL-4 and IL-10 cytokines, with the former mainly produced by TILs and the latter by adherent, TIL-depleted cells [74].