Recent findings report different cases in which CSF biomarkers are useful at different stages of AD diagnosis and in different ages; in particular, CSF Aβ42 assays have good agreement with amyloid PET imaging, while Aβ42/Aβ40 and tau/Aβ42 ratios have superior performance to Aβ42 alone [23,24]. Here, MAPT is linked to Alzheimer disease.