MAPT and Alzheimer disease: In line with the recent hypothesis of an infectious trigger in AD pathogenesis [9], in vitro evidence suggests a direct role of HIV, or of some of its components (such as tat ang gag proteins), in favoring amyloid beta misfolding and plaque aggregation, as well as in promoting neuronal injury, tauopathies, and the hyperphosphorylation of tau proteins [10,11,12].