PTGDR and hepatocellular carcinoma: E2F1 regulates HCC progression through multiple pathways; Shen et al. showed that E2F1 activates KDM4A-AS1 via the PI3K/AKT pathway [57], while Lei et al. suggested that ARRB1 plays a critical role in HBV-related HCC by modulating autophagy and the CDKN1B-CDK2-CCNE1-E2F1 axis [58].