TP53 and hepatocellular carcinoma: For example, retrotransposon Gag like 1 (HuR1) interacts with tumor protein p53 (p53) and represses the transcriptional regulation of downstream genes such as cyclin kinase inhibitor (p21) and bcl2-associated X (Bax) in Hepg2 cells, promoting the proliferation of hepatocellular carcinoma cells [12].