APP and Alzheimer disease: For instance, ablation of astrocytes and proliferative astrocytes in organotypic 5xFAD brain culture slices and 9-month-old APP23/GFAP-TK mice [APP23 is a mouse model overexpressing a human APP with a Swedish mutation (Sturchler-Pierrat et al., 1997) crossed with glial fibrillary acidic protein (GFAP) thymidine kinase (TK) mice], respectively, both showed increased levels of Aß, indicating a crucial role for astrocytes in the resolution of AD pathology (Katsouri et al., 2020; Davis et al., 2021).