Levels are reduced in CKD. NOS inhibition causes systemic and glomerular hypertension, glomerular ischemia, glomerulosclerosis, tubulointerstitial injury, and proteinuria [161]. Presence of the two NOS3 gene polymorphisms, Glu298Asp polymorphisms 4 b/a and -786T > C is a risk of ESKD in patients with CKD and ADPKD [162,163]. The gene discussed is NOS2; the disease is autosomal dominant polycystic kidney disease.