MAPT and diabetes mellitus: Given that DM patients have a higher risk of developing AD in the process of ageing as compared to non-DM control subjects [44], and that neurodenegeration mediated by abnormal tau is implicated in both AD and DM-related cognitive dysfunction [45], it is imperative to elucidate the potential molecular mechanisms underlying the DM induced-neurodegeneration so that to provide appropriate clinical interventions with aims to decrease or remove the risk of developing AD in this DM population.