Indeed, its key biomarkers, such as Aβ in the cerebrospinal fluid (CSF), deviate from normality ≈ 25 years before symptom onset, whereas tau protein levels and hippocampal volume changes emerge at ≈ 15 years, and cognitive impairments becoming apparent ≈ 5 years, before the onset of clinical symptoms.12 The gene discussed is MAPT; the disease is Cognitive impairment.