SMAD4 and liver cancer: Gao et al. (2019) have found that the levels of SMAD2, SMAD3, and SMAD4 in liver cancer are significantly elevated. Autophagy plays an important regulatory role in liver fibrosis and HCC,and autophagy-related gene signatures can be used as a biomarker to predict clinical outcomes of HCC (Shen & Lin, 2019; Mao et al., 2020).Owing to the close relationship between liver fibrosis and liver cancer.