TNFRSF9 and neoplasm: CD137 bispecific molecules with similar potency to urelumab in combination with PD-1 blockade should be assessed in clinical trials because CD137+ TILs also express PD-1, and CD137 bispecific molecules in combination with anti-PD-1 mAb demonstrated the best synergistic effect in preclinical model systems, when compared with either CTLA-4 or TIM3 targeting molecules by enhancing terminally differentiated CD8+ T cells in tumor [61].