That is, CSF p-tau probably changes early in the disease course, and plateaus in early AD [76, 78, 84, 124], while [18F]flortaucipir PET likely becomes abnormal after CSF tau biomarkers [76] and continues to increase over time with advancing disease stage [2, 19, 40, 41, 47, 96]. The gene discussed is MAPT; the disease is Alzheimer disease.