IL17A and interstitial lung disease: Recently, IL17 has been proposed as a pro-inflammatory mediator (similar to TNFα and TGF-β) involved in ILD development, as demonstrated in rat models, where both IL17 and TNFα (together with other cytokines) were increased (after bleomycin induction of ILD) in the lung tissue samples after hematoxylin-eosin staining [54].