Dyrk1A-IN-5 (compound 5j) is a potent and selective DYRK1A inhibitor, with an IC 50 of 6 nM. Dyrk1A-IN-5 dose-dependently reduces the phosphorylation of Thr434 in SF3B1, with an IC 50 of 0.5 μM. Dyrk1A-IN-5 inhibits phosphorylation of tau at Thr212, with an IC 50 of 2.1 μM. Dyrk1A-IN-5 can be used for Down syndrome research Form:Solid IC50& Target:DYRK1A 6 nM (IC 50 ) DYRK1B 600 nM (IC 50 ) DYRK2 >10000 nM (IC 50 )