NOX4 and polycystic ovary syndrome: In another study, Yanes, et al. used the dihydrotestosterone (DHT)-treated rat model of PCOS and found that the mRNA expression levels of NOX subunits, p22(phox), p47(phox), gp91(phox), and NOX4 were all upregulated in the kidneys compared to control females [84]; however, mitochondrial function was also not measured in this study.