Editorial [Hot Topic: GSK-3 in Health and Disease (Guest Editor: H. Eldar-Finkelman)]

Protein kinases play essential roles in cellular processes and are well recognized as important therapeutic targets in many human diseases. The serine/threonine protein kinase Glycogen synthase kinase-3 (GSK-3) is an extraordinary example in this regard. This enzyme, which was characterized originally as a glycogen synthase kinase, has emerged, unexpectedly, as a drug-discovery target in several pathological disorders, including diabetes, affective disorders, and Alzheimer's disease. The unique biochemical and cellular features of GSK-3, which distinguish it from other protein kinases, are most likely the key to understanding the sophisticated function of GSK-3 in biological systems. These features justify the efforts invested toward the development of selective GSK-3 inhibitors as a promising therapeutic treatment. In this issue of Current Drug Targets, articles are gathered from eight groups with different expertise areas that, together, uncover the multiple aspects of GSK-3. This gives the reader a unique, special opportunity to gain a panoramic view in the filed, and to uncover the challenges that still wait to be resolved.