Immunohistochemical analysis of brains from APP transgenic mice, a model of AD, revealed that SUMO1 co-localizes with hyperphosphorylated tau in neurites associated with amyloid plaques suggesting that tau SUMOylation is a downstream effect mediated by pathological Aβ amyloid plaques (Takahashi et al., 2008). Here, APP is linked to Alzheimer disease.