IFNG and neoplasm: ICI-activated cytotoxic CD8+ T cells released IFN-γ, promoting tumor FGF2 signaling, thereby inhibiting PKM2 activity and reducing NAD levels, enhancing SIRT1-mediated acetylation of β-catenin, ultimately activating the Wnt-β-catenin pathway and leading to HPD [140] (Fig. 4).