STAT3 and neoplasm: Here, we performed comprehensive global protein expression profiling, which showed an upregulation of mTOR and CREB signaling pathways (Fig. 3C) in Ptenpc−/−Stat3pc−/− tumor cells, suggesting a critical negative regulatory role of STAT3 for mTORC1 and CREB signaling in PCa tumorigenesis and metastatic formation.