Moreover, within a panel consisting of 29 cytokines, and including total tau protein, p-tau181, Aβ1–40, and Aβ1–42, a high level of circulating IL-2 was found to be the best-performing biomarker to predict a slower cognitive decline in MCI patients (measured by a two-point decrease, or more, in the MMSE), though no reliable biomarker was found in AD patients [120]. This evidence concerns the gene MAPT and Alzheimer disease.