PIK3CA and Familial prostate cancer: As EGFR and PDGFR signal through downstream pathways, mainly the PI3k-mTOR and the Erk1/2 pathway, and these routes have also been implicated in the androgen-independent control of the AR in prostate cancer, we evaluated if the inhibition of these central nodes could have more effect on the expression of the AR than individual inhibition of RTKs.