Furthermore, proinflammatory cytokines down-regulate eNOS expression and their levels are correlated with a progressive impairment of the endothelial function; in addition, the overexpression of TNF-α may aggravate skeletal muscle atrophy and is associated with impairment of exercise capacity, a common feature in HF patients [43,44,45]. This evidence concerns the gene NOS3 and hydrops fetalis.