When Aβ1-42 and t-tau are considered together (Aβ1-42 to t-tau ratio), the sensitivity and specificity of diagnosing AD is more than 85%.33 Huded, et al. in a study from southern India also found that p-tau/t-tau and p-tau/Aβ ratio are good indicators of severity of dementia and may help differentiate between mild AD and moderate to severe AD.34 Different phosphorylated epitopes of tau may also be helpful in distinguishing AD and FTD (p-tau231) or AD and DLB (p-tau181).35,36. This evidence concerns the gene MAPT and Alzheimer disease.