SIRT1 and diabetes mellitus: As for the mechanism(s) underlying the protective role of sirtuin-1 in diabetes-induced endothelial dysfunction, a recent study showed that sirtuin-1, through its deacetylase activity, suppresses the capacity of the 66-kDa Src homology two domain-containing protein (p66Shc) to induce vascular oxidative stress (Kumar et al., 2017).