The hyperphosphorylation of tau protein leads to the formation of neurofibrillary tangles (NFTs), resulting in the impairment of normal axonal transport, synaptic loss, and neuronal function impairment, which drives neurodegeneration and is closely related to T2DM (Ke et al., 2009; Oliveira et al., 2021). Here, MAPT is linked to type 2 diabetes mellitus.