MED1 and hepatocellular carcinoma: Using the CRISPR/Cas9 gene-editing approach, knockout of BRD4, MED1 and CDK7 significantly represses cell proliferation and colony formation in both Huh7 and HepG2 cell lines in vitro (Tsang et al., 2019), suggesting that the components of the SE complex may serve as therapeutic targets for HCC.