MS049 does not inhibit any of the methyltransferases at 50 μM or demethylases at 10 μM and does not display appreciable binding to any of the methyllysine/methylarginine reader proteins using the DSF assay at 200 μM. MS049 demonstrated excellent selectivity over a broad range of epigenetic and nonepigenetic targets. In cellular assays, MS049 potently inhibits the methyltransferase activity of PRMT4 and PRMT6 and reduces levels of Med12me2a and H3R2me2a in HEK293 cells.