NOX-4 is an important profibrotic signal implicated in aberrant fibroblast activation in idiopathic pulmonary fibrosis [32], and TGF-β1-mediated collagen type I gene, α-SMA, and fibronectin-1 gene expressions were Nox4-dependent [33, 34]. The gene discussed is NOX4; the disease is pulmonary fibrosis.