MAPT and Alzheimer disease: Cerebrospinal fluid (CSF) levels of Aβ1–42 protein (Aβ), total tau protein (T-tau), and phospho-tau protein 181p (P-tau) have been shown to have a diagnostic utility for discriminating AD dementia cases from cognitively normal controls [3], early recognition of patients with MCI due to AD or dementia due to AD [4, 5].