NOX4 and Hyperglycemia: A significant increase in the mRNA and protein levels of Nox1 (mRNA ≈ 3-fold; protein ≈ 2-fold), Nox2 (mRNA ≈ 2-fold; protein ≈ 2.7-fold), and Nox4 (mRNA ≈ 4-fold; protein ≈ 1.85-fold) isoforms were determined in the kidney of diabetic mice after 4 weeks of hyperglycaemia.