NOX4 and chronic kidney disease: Nox4 has a renoprotective action in the unilateral ureteral obstruction (UUO) mouse model of CKD (Decleves and Sharma, 2014), and Nox4-deficient mice exhibited elevated tubulointerstitial fibrosis and oxidative stress after obstruction, and reduced levels of antioxidant markers, including hypoxia-inducible factor 1α and Nrf2.