The tau protein in NFTs is mainly C-terminal truncated, and half of the tau protein in cerebrospinal fluid (CSF) does not contain the C-terminal portion of MTBR.AD brain contains a large number of high molecular weight tau protein aggregates (HMW-tau) resistant to sodium dodecyl sulfate (SDS) and reducing agents, and there is no N-terminal region. The gene discussed is MAPT; the disease is Alzheimer disease.