PTOV1 and Familial prostate cancer: Together with our observations that PTOV1 expression correlates positively, and HES1 expression negatively, with prostate cancer progression, these evidences may suggest that both PTOV1 and p300, which antagonize Notch target transactivation, function as positive inducers of prostate cancer progression, whereas the Notch signaling and the HES1 activator CBP function as suppressors of prostate cancer establishment and/or progression.