Consequently, we measured the plasma levels of Aβ40, Aβ42, P-tau181, NfL, and GFAP in 1007 participants without dementia, aged 79–94 years and enrolled in the longitudinal population-based German Study on Ageing, Cognition and Dementia in Primary Care Patients (AgeCoDe). The gene discussed is GFAP; the disease is dementia.