Striatal GSK-3B may be upregulated in HD since serine 9 phosphorylation of GSK-3β negatively regulates GSK-3β, and it was shown that this phospho-GSK-3β was reduced in both the striatum and cerebral cortex at the onset of behavioral manifestations in both N171-82Q and YAC128 HD transgenic mice [44]. Here, GSK3B is linked to Huntington disease.