Thus, NOX4 may be relevant in the bleomycin model, but this model may not reflect the wide spectrum of human lung fibrosis (idiopathic, radiation, silicosis, systemic lupus erythematosus, dermatomyositis, sclerodermia, rheumatoid arthritis, pneumoconiosis, acute respiratory distress syndrome, chronic heart failure, drug-induced). Here, NOX4 is linked to pulmonary fibrosis.