To explore the relationship between cholinergic markers and the AD biomarkers, an exploratory analysis was done on subgroups which were positive or negative with regards to CSF levels of the AD biomarkers: Aβ42+ vs. Aβ42− (cut-off 650 pg/ml), t-tau+ vs. t-tau− (cut-off 400 pg/mL), or p-tau+ vs. p-tau− (cut-off 78 pg/mL). The gene discussed is MAPT; the disease is Alzheimer disease.