Researchers noticed that the availability and function of endothelial NO were likely to be compromised if endothelial zinc stores became depleted in conditions of zinc deficiency [12], while interestingly, clinical studies showed that patients with iHTN had a significant decrease of the NO/ET-1 balance at the end of HD compared with control patients [9], potentially suggesting that zinc deficiency might play an important role in iHTN via the decreased NO/ET-1 balance. The gene discussed is EDN1; the disease is Huntington disease.