Phosphorylated epitopes of tau (p-tau) can be measured in CSF as well; while most phospho-epitopes of tau are also found in healthy non-diseased brains and are not AD-specific, pathological tau species overall are highly phosphorylated in AD (Matsuo et al., 1994) and this altered state reflects the elevated levels of p-tau seen in AD. The gene discussed is MAPT; the disease is Alzheimer disease.