When ADAR1 isoforms are over-expressed, the expression levels of COL3A1 and SMAD2 mRNA are modified, ADARp-110 induces downregulation of COL3A1 and SMAD2, and interestingly ADARp-150 induced an increase in COL3A1 on both normal and IPF fibroblasts. Here, COL3A1 is linked to idiopathic pulmonary fibrosis.