CHEK1 and hepatocellular carcinoma: A previous study has also shown that ultraviolet light enhances the DNA damage of HepG2 cells after knockdown of ERH. ERH regulates the splicing of DNA damage response protein, i.e., ataxia telangiectasia and Rad3-related protein, in HCC cells and targets the DNA damage response by Chk1 inhibitors to enhance chemotherapy against HCC cells (7).