TNF and interstitial lung disease: However, it does not represent a model of chronic and progressive pulmonary damage with inflammation and fibrotic remodelling.32 Our RA‐ILD model in D1CC mice manifests chronic and immunologically inflammatory and progressive interstitial pneumonia with increased TNF‐α, IL‐6 and TGF‐β levels; thus, it can be considerably important as a model of RA‐ILD and chronic progressive interstitial pneumonia in humans, which is valuable for the future evaluation of biomarkers and treatments.