AR and prostate adenocarcinoma: In patient-derived xenograft systems modeling the progression of prostatic adenocarcinoma to SCNC, it was observed that the placental gene PEG10 becomes de-repressed and highly up-regulated.88 It was found that both AR and E2F/Rb pathways dynamically regulate distinct isoforms of PEG10 at different stages of SCNC development and that PEG10 was able to drive cell cycle progression in the context of p53 loss as well as promote invasion through up-regulated Snail expression and TGF-β signaling.