MAPT and Alzheimer disease: Tauopathies are a class of over 20 degenerative disorders, including AD, marked by neuronal aggregation of abnormally phosphorylated forms of the protein tau, a microtubule associated protein (MAPT) essential for microtubule assembly and stability ((Grundke-Iqbal et al., 1986; Williams 2006; Spillantini and Goedert 2013).