A 1070722 is a potent and selective glycogen synthase kinase 3 (GSK-3) inhibitor, with a Ki of 0.6 nM for both GSK-3α and GSK-3β. A 1070722 can penetrate the blood-brain barrier (BBB) and accumulates in brain regions, thus potential for PET radiotracer for the quantification of GSK-3 in brain.