IRS1 and type 2 diabetes mellitus: The maintenance of cognitive function in exercising T2DM rats treated with dexamethasone, demonstrated by De Sousa et al. (2020), was according to the authors presumably mediated by the observed lesser inhibition of the activation of hippocampal IRS-1 and higher concentration of GSK3β phosphorylated on serine-9 (Ser-9) [115].