The main two CNI drugs namely, cyclosporine A (CsA) and tacrolimus (Tac), have been suggested to impair vascular endothelial function via decreased generation of NO release along with increased generation vasoconstrictor peptide, endothelin-1 (ET-1) that leads to elevated vascular tone and resultant hypertension [4–8]. The gene discussed is EDN1; the disease is hypertensive disorder.