INS and type 2 diabetes mellitus: Zinc-deficient β cells have been shown to have fewer insulin granules and suffer from greater oxidative stress than zinc-replete cells (14), effects that are primarily a result of changes in metal-binding metallothionein proteins as well as zinc transporters of the Zrt- and Irt-like protein (ZIP) and zinc transporter (ZnT) families, among which, ZnT8 has been shown to be particularly important for the pathophysiology of T2D (14, 19).