To explore whether NKTR-214 could improve T-cell-mediated antitumor immunity induced by PD-1 CPI therapy, we evaluated the efficacy of anti-PD-1 or NKTR-214 alone and in combination, in eight different tumor models of colon, ovarian, bladder, liver, pancreatic, breast and lung cancer, and melanoma in the four different mouse strains BALB/c, C57BL/6, C3H, and FVB. This evidence concerns the gene NKTR and neoplasm.