In controls, all biomarkers were positively associated with age at interview (P-value ranked between 1.2 × 10−7 for Aβ42 and 1.9 × 10−30 for NfL) and negatively with the ratio Aβ42/Aβ40 (P = 1.2 × 10−10) (see Table 3), indicating that all biomarkers are sensitive to age and will show less discrimination between AD cases and controls if AD cases with earlier onset (∼65–68 years) are compared with elderly screened controls (Supplementary Fig. 1). The gene discussed is NEFL; the disease is Alzheimer disease.