Of relevance to the role of NOX4 in the fibrotic process of SSc are recent studies demonstrating that ROS were capable of inducing the phenotypic conversion of quiescent fibroblasts and endothelial cells into activated myofibroblasts through fibroblast-myofibroblast and endothelial to mesenchymal transition (EndoMT) phenotypic changes, respectively [92,93,94,95,96]. This evidence concerns the gene NOX4 and systemic sclerosis.