NOX4 and diabetes mellitus: Previously in this model of T1D, we have shown that the expression of LV NADPH oxidase subunits p47phox and Nox2, along with increases in superoxide levels (measured by lucigenin chemiluminescence), gene expression of Nox4 and protein abundance of PKCβ2, were significantly upregulated after 12–14 weeks of diabetes (Huynh et al., 2013; Prakoso et al., 2017).