NOX4 and chronic kidney disease: However, aortic expression of NOX2 and NOX4 were higher in CKD animals compared with normal animals (Fig. 3C, D), and treatment with GKT alone or in combination with KP in CKD rats led to lower NOX4 expression in the aorta but did not alter NOX2 expression compared with non‐treated CKD rats, demonstrating the efficacy and specificity of the inhibitor (Fig. 3D).