NOTCH1 and prostate cancer: Conflicting reports exist on a possible tumor suppressing or promoting function of Notch in (human) prostate cancer: several works suggest that Notch1 may act as a tumor suppressor in this specific tissue and its signalling is lost in prostate adenocarcinomas [22, 23]; other surveys have demonstrated that Notch1 expression augments in human prostate tumor specimens with increasing tumor grade and that Notch1 knockdown decreases cell invasion [24, 25].