CD4 and squamous cell carcinoma: TIM-3 has been initially observed on terminally differentiated IFNγ-producing CD4+ Th1 cells and CD8+ cytotoxic T cells [165, 166], as well as on Th17, DCs, monocytes, Tregs, mast cells, NK cells, TILs and tumor cells, including melanoma, squamous cell carcinoma, gastric cancer and NSCLC cells, but not on CD4+ Th2 cells [154].