TIGIT is found to be expressed by tumour-infiltrating lymphocytes (TILs) in NSCLC and ‘distant lung-associated lymphocytes’ (DLALs), but also by peripheral blood mononuclear cells (PBMCs) and, less significantly, tumour-free lung lymphocytes (TFLLs) [20,21]. This evidence concerns the gene TIGIT and neoplasm.