HAVCR2 and neoplasm: Another important co-inhibitory receptor, Tim-3 was initially found to be expressed in CD4+ type 1 helper T cells (TH1 cells) and CTLs.6 Subsequently, Tim-3 was detected on Tregs, myeloid cells, NK cells, and tumor cells.6 At present, it is considered that blockade of Tim-3 signaling can be used as a supplement to the failure of anti-PD-1/PD-L1 therapy.