Because p68 siRNA decreases the levels of AR, and p68 regulates PDGFR-β upon PDGF stimulation, we therefore believe that there is regulatory axis of p68-PDGFR-β-AR in PDGF-BB and androgen signaling, wherein p68 and PDGFR-β co-regulate AR expression in breast cancer cells. The gene discussed is AR; the disease is breast cancer.