KLK3 and prostate cancer: Expression vectors for the human AR cDNA containing 9, 24, and 35 polyQ tracts and for AR cofactors, including ZMIZ1, ZMIZ2, and ARA70, were co-transfected with an androgen-induced luciferase reporter driven by a 7 Kb PSA promoter-enhancer fragment into prostate cancer cell line, DU145.