Reactive astrocytes were also seen around penetrating vessels that were again not necessarily co-labeled with Thioflavin S; however, the large, loose clusters of cortical astrocytes were the most prominent aspect of gliosis in this model, and contrasted with a more pronounced response to cerebral amyloid angiopathy in the Nestin-Cre;R26-APP animals. The gene discussed is APP; the disease is cerebral amyloid angiopathy.