RB1 and prostate cancer: RB1 dysregulation is a hallmark of prostate cancer, primarily recognized for its role in regulating the cell cycle through interactions with the early 2 factor (E2F) family of transcription factors, particularly E2F1.10, 11, 12 Notably, given the fundamental role of the E2F family in normal cellular processes, directly targeting the E2F family may not be desirable because of the potential for in vivo toxicity, although several agents, such as the pan-E2F inhibitor HLM006474 and the nucleoside analog LY101–4B, have been reported to suppress cancer growth in vitro.13