PIK3CA and prostate carcinoma: Many other signaling pathways that interact with the PI3K and TGFβ signaling cascades have also been implicated in mediating CAF activity, including the mitogen-activated protein kinase (MAPK), WNT, Janus kinase/signal transducer and activator if transcription proteins (JAK/STAT), endothelial growth factor receptor (EGFR) and Hippo signaling cascades (reviewed in [135]); however, to date there has been little research to ascertain whether these signaling pathways regulate CAF activity in prostate cancer.