TNF and erectile dysfunction: Lifestyle modifications, including physical exercise, are in fact suggested as a first-line treatment for erectile dysfunction [43], since exercise improves bioavailability of nitric oxide and increases the number of endothelial progenitor cells, while at the same time diminishing concentrations of markers of oxidative stress [44] and expression of TNF-α, IL-1-beta and IL-6, therefore improving endothelial function [45] and consequently reducing the risk for erectile dysfunction [46].