Thus for the diagnosis of AD, one should assess the brains regarding the occurrence of both hyperphosphorylated tau (HP‐tau) a protein which is found both in its soluble (pre‐tangles and NTs) and insoluble (NFT and NTs) forms and also β‐amyloid (Aβ) protein which is found as variform plaques in parenchyma and is present in cerebral amyloid angiopathy (CAA) in vessel walls. The gene discussed is MAPT; the disease is Alzheimer disease.