RB1 and cancer: Since then, many research groups have reported on the pleiotropic cancer-related functions of ATAD2 through a variety of signaling pathways, such as the steroid hormone signaling pathway, the retinoblastoma (Rb)/E2F-cMyc pathway, the AKT pathway, the hedgehog signaling pathway (HH), the hypoxia inducible factor 1α (HIF1α) signaling pathway, and the p53 and p38-MAPK-mediated apoptotic pathway in diverse cancer types [6,7,8,9,10,14].