Considering the critical role of insulin in maintaining glucose homeostasis and regulating metabolic processes, coupled with its intricate association with synaptic plasticity, learning and memory, the studies of Salvatore et al. have defined a new pathophysiological pathway that may pave the way for new approaches in comprehending the connection between insulin signaling and tau, and for the development of innovative therapeutic approaches simultaneously targeting diabetes mellitus and tauopathies. This evidence concerns the gene MAPT and diabetes mellitus.