In this study, we quantified the levels of total tau (t-tau), along with neurofilament light (NfL) and glial fibrillary acidic protein (GFAP), in saliva samples from 111 participants, including those with CSF biomarker-confirmed AD, mild AD, non-AD cognitively impaired (CI) and cognitively unimpaired (CU) older adults, using immunoassays on the Meso Scale Discovery platform. This evidence concerns the gene MAPT and Alzheimer disease.