Abstract: Pulmonary fibrosis is a refractory disease with high mortality. The expression of NOX4 mRNA can be activated and increased by TGF-beta1 which could induce the production of a large number of ROS. ROS could further activate Smad which involved in mediating the signaling pathway of TGF-β1/Smad leading to the occurrence of pulmonary fibrosis. Blocking the expression of NOX4 gene through varieties of technologies would disturb the signaling pathway of TGF-β1/Smad which may block the progress of pulmonary fibrosis. Therefore NOX4 may be the most promising therapeutic target in the process of pulmonary fibrosis.

Key words: acute lung injury, NOX4, pulmonary fibrosis , ROS, TGF-β1