SMAD2 and hepatocellular carcinoma: Zhaowei Qu et al. conducted a comprehensive bioinformatics study on the potential molecular mechanisms of TGF-β activation in HCC cells, and found that TGF-β may affect the biological processes of HCC cells via regulatory pathways such as SMAD2/SMAD3-NEDD4 and HNF4A-CUL4 B/NEDD4, which provides a new direction for further research on HCC [140].