MAPT and Alzheimer disease: Exposure to a history of repetitive mild traumatic brain injury (mTBI) has been recognized as a major risk factor for the development of age-related degenerative diseases, such as Alzheimer’s disease, and chronic traumatic encephalopathy (CTE) typified by immunoreactive tau aggregates in the depths of the sulci (Gedye et al., 1989; Mortimer et al., 1991; Schofield et al., 1997; Fleminger et al., 2003; McKee et al., 2013; Omalu et al., 2011; Smith et al., 2013).