Three different types of pools of tau are found the in the brains of AD patients: (a) AD tau is most similar to normal tau and is not hyperphosphorylated; (b) AD Phosphorylated tau (AD P-tau) is soluble hyperphosphorylated tau, and (c) paired helical filaments (PHFs)-tau is insoluble and hyperphosphorylated [113]. This evidence concerns the gene MAPT and Alzheimer disease.