A recent study revealed 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 [81]. Here, PDCD1 is linked to cancer.