Potent and selective DYRK inhibitor (IC50 = 0.7 nM for DYRK3, similar potency for DYRK1 and 2). Exhibits ~20-fold selectivity over casein kinase 2 and negligible activity against a panel of 451 kinases screened. Enhances number of CFU-E stimulated by Epo from human marrow. Increases hemoglobin levels in anemic mice. Orally bioavailable. Purity 98%. MW (observed): 401.27