Active Motif's TC-E-5003 is a selective protein arginine methyltransferase 1 (PRMT1) inhibitor (IC50 = 1.5 uM). It displays no activity against CARM1 and Set7/9 methyltransferases. TC-E-5003 inhibits the growth of MCF-7 breast cancer cells and LNCaP prostate cancer cells. It blocks androgen-induced gene expression in LNCaP cells.