E2F1 and hepatocellular carcinoma: Numerous studies indicate that E2F1 transcription factor is one of the most in-depth E2Fs family members in tumor research, and the high expression of E2F1 is of great significance for the poor prognosis of malignant tumors such as gastric cancer [35], hepatocellular carcinoma [36], pancreatic cancer [37], and prostate cancer [38].