Consistent with our findings, combined inhibition of PD-1 and activation of AMPK by Metformin, AICAR or BME had currently been proposed to double response rates in suppressing cell growth of different types of cancers and yielding a substantial increase in the number of tumor-infiltrating CD8+ T cells in mouse models [75,76,77,78], supporting the potential clinical use of AMPK activators when combined with anti-PD-1 ICIs. Here, PDCD1 is linked to cancer.