This value is close to the P50 value for disaggregation of PHFs isolated from AD brain (0.16 μm), the minimum brain concentration (0.13 μm) required to reverse behavioral deficits and reduce Tau pathology in Tau transgenic mice (12), and the estimated steady state trough brain concentration of MT and its pharmacologically active demethyl derivatives (0.18 μm) at the minimum effective dose found to be required for arresting the progression of AD (11). This evidence concerns the gene MAPT and Alzheimer disease.