ATF3 and pulmonary fibrosis: This review briefly discusses the mechanism of action of ATF3 and its effects on biological functions and cellular processes, with a special focus on the role of ATF3 in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF), and with an overall aim to identify new targets for the treatment of inflammatory pulmonary diseases.