In order to confirm the competitive nature of harmol antagonism in a prostate cancer context, we tested the antagonist effects of harmol in PC-3 cells stably overexpressing AR (PALM cells also referred to as PC3 hAR MMTV-luc cells), in the presence of various concentrations of R1881 (0.1, 0.3, 1, 10 nM) using the same transactivation assays (Supplementary Figure S2). The gene discussed is AR; the disease is prostate cancer.