Moreover, it has been shown that the downregulation of NNMT contributes to the survival of HCC cells by enhancing autophagy under nutrient starvation, thus autophagy inhibitor therapy may provide a possible therapeutic intervention for HCC by inhibiting NNMT (Roberti et al. 2021; Shin et al. 2018). This evidence concerns the gene NNMT and hepatocellular carcinoma.