MAPT and Alzheimer disease: Neurofibrillary tangles composed of hyperphosphorylated tau is a neuropathological hallmark of AD but not VCID (Mattson, 2004; Goedert and Spillantini, 2006; Roberson and Mucke, 2006; Ballatore et al., 2007; Spires-Jones et al., 2009).