ASCL1 and prostate adenocarcinoma: Remarkably, sustained induction of YAP15SA (or wild-type YAP1) starting 2 weeks after transplantation prevented the appearance of any detectable ASCL1+ cells in PRAD tumors that emerged 21 days later, whereas tumors that developed from RPM organoids transduced with the Dox empty vector control (EV) had abundant regions of ASCL1+ NEPC (Fig 4I–J), indicating that sustained YAP/TEAD activation can prevent PRAD to NEPC lineage plasticity in vivo.