CHEK1 and hepatocellular carcinoma: Activation of DNA-PKcs regulates various tumor-promoting molecules, such as maintaining the stability of Snail1, Chk1–Claspin complex, or enhancing the transcriptional activity of p53 and androgen receptor (AR), and resultantly mediates the progression of colon cancer, prostate adenocarcinoma, hepatocellular carcinomas (HCC) and other human cancers [20–23].