In vitro, CDA1 overexpression by lentivirus infection in human embryonic lung fibroblasts (HFL1 cells) inhibited the production of pro-fibrotic and pro-inflammatory cytokines, lung fibroblast-to-myofibroblast transition, and extracellular matrix protein expression induced by exogenous TGF‐β1 treatment, whereas CDA1 knockdown with small interfering RNA promoted this effect. This evidence concerns the gene TGFB1 and lentivirus infection.