By way of example, CSF Aβ1-42 has been used as an alternative to amyloid PET in the screening phase for AD trials to accommodate geographies with differing availability of the two methods [9], and CSF markers of Aβ and tau (phosphorylated tau and total tau) have been frequently used as alternative outcome biomarkers reflecting disease pathology [5, 9, 10, 197, 198]. The gene discussed is MAPT; the disease is Alzheimer disease.