GSK3368715 is an orally active type I PRMT inhibitor. Protein arginine methyltransferases (PRMTs) transfer a methyl group from S-adenosyl-L-methionine (SAM) to the substrate arginine side chain. All PRMTs can generate ω-NG-monomethyl-arginine (MMA) through a single methylation event. However, type I and II enzymes catalyze progression from MMA to NG-asymmetric...