The study provides evidence that PD-1 interacts with Gal-9 and TIM-3 to attenuate Gal-9/TIM-3-induced apoptosis of PD-1+TIM-3+ T cells in cancers, and demonstrates that Gal-9 is upregulated by the inflammatory cytokines IFNβ and γ, and targeting Gal-9 can be an effective strategy for cancer immunotherapy. Here, PDCD1 is linked to cancer.