TIGIT and head and neck squamous cell carcinoma: Both studies suggest that TIGIT is highly expressed on CD8+T and Treg cells in MM or HNSCC TILs and that anti-TIGIT mAbs reverse TIGIT-mediated suppression of CD8+T cell effector functions; however, the potent anti-tumor effect of anti-TIGIT mAbs as a single agent may not be fully guaranteed simply by the increased expression of TIGIT in TILs, since high TIGIT expression is also observed in CD8+ TILs in CT26-bearing mice that are not responsive to TIGIT blockade [42].