Chemotherapeutic agents can promote MHC-I or NKG2D ligand upregulation by tumor cells and to sensitize them to Fas or TRAIL mediated apoptosis [19,20], but it is unclear whether this occurs mainly in tumor cells destined to die from chemotherapy-induced cytotoxicity or the fraction of cells surviving the chemotherapeutic insult. This evidence concerns the gene KLRK1 and neoplasm.