PrEC, RWPE1, LNCaP and VCaP cells were grown in their regular medium and harvested when cultures reached 70-80% confluence. Equal amounts of protein were analyzed by western blot using antibodies directed against SRC1, SRC2, SRC3, p300 and CBP. As an internal loading control, blots were stripped and reprobed with an antibody recognizing beta-actin (β-act).