Finally, in line with the CSF cut-off levels used to distinguish AD patients from healthy controls [28], and considering that the different diagnostic categories established by Engelborghs and co-workers [19] are supported by the reported CSF biomarker profiles, it is important to contemplate that although our MCI participants might be in a very prodromal disease stage (i.e., with higher Aβ-42 and lower t-tau and p-tau levels), their CSF biomarker profile may not match the conventional pattern seen in AD (i.e., lower Aβ-42 values and higher t-tau and p-tau levels). The gene discussed is MAPT; the disease is Alzheimer disease.