IFNG and hepatocellular carcinoma: NK cells display anti-HBV roles and mediate liver inflammation, which promotes the development of HCC by producing IFN-γ [10,11]; meanwhile, their antiviral activities are suppressed by regulatory cells and cytokines, and feature upregulated inhibitory receptors NKG2A, TIM-3 and PD-1, and reduced IFN-γ and TNF-α production [11,12,13].