NOX4 and pulmonary fibrosis: From the family members of the NOX, the isoforms Nox1, Nox2 and Nox4 have been found to be implicated in the pathogenesis of pulmonary fibrosis but not Nox3 (Masamune et al., 2008; Griffith et al., 2009; Amara et al., 2010).