Potent and selective ATP-competitive Dyrk1B kinase inhibitor (IC50 = 7 nM); displays distinct cellular effects when compared to DYRK1B knockdown through siRNA. Demonstrates cellular in vitro activity (IC50 = 194 nM). Exhibits better selectivity than AZ 191 (Cat. No 5232); displays no off-target effects against a panel of 124 kinases tested (no kinase was inhibited above 50% at 1 μM). Purity 98%. MW (observed): 300.36