The immunoreactivity of the staining for glial fibrillary acidic protein (GFAP) in the astrocytes is also significantly higher in the caudate nucleus in HD brains compared to in healthy brains, and there is also increased reactive astrogliosis with elevated Cx43 expression associated with degenerating neurons (Vis et al., 1998). The gene discussed is GJA1; the disease is Huntington disease.