MAPT and Alzheimer disease: The AD-related biomarkers beta-amyloid (1–40) (Aβ1-40), beta-amyloid (1–42) (Aβ1-42), total Tau (tTau) and Tau phosphorylated at threonine 181 (pTau(181)) have gained great importance [[4], [5], [6]] and are of essential use for laboratory analytics supporting the clinical diagnosis [3,7].