NEFL and Alzheimer disease: We then created three separate OPLS-DA models consisting of the traditional AD biomarkers (Aβ1−42/Aβ1−40, p-tau181, and NfL; Fig. 2c), the 13 key discriminator protein panel (Fig. 2d), and the 13-protein panel plus the AD biomarker set together (Fig. 2e).