Consequently, it was shown that metformin regulates the remodeling of the small conductance calcium-activated potassium channels (SK2 and SK3) in the atrial tissues of a rat model of type 2 diabetes mellitus through the inhibition of NOX4 expression (constitutive NAPDH oxidase), but also by significantly suppressing the p38–MAPK signaling pathway (Liu et al., 2018). This evidence concerns the gene NOX4 and type 2 diabetes mellitus.