HAVCR2 and neoplasm: In fact, TIM-3 is widely expressed on T antigenic tumor-specific lymphocytes, in peripheral blood and in tumor-infiltrating lymphocytes (TIL), both CD4+ and CD8+ [37], and overexpressed on so-called exhausted T cells (especially CD8+ and CD4+ Treg Foxp3+) in tumor settings [12,15].