Regarding the endothelial dysfunction in SSc, there is evidence of reduced intracellular eNOS production in the SSc endothelium and increased endothelial activation [10,11,12,13,14,15,16,17,18,19,22,23,24,25,40,41,42,43,44,45,46,47,48]. Here, NOS3 is linked to systemic sclerosis.