IL4 and pulmonary fibrosis: Once accepted that A. suum infection and pulmonary fibrosis displayed a common Th2/Th17 cytokine pathway that determines the pathology progression [1,6,24,28], we verified whether there is some interference during comorbidity, in specific pathways of immune response involving the production of IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17A, IL-33, TGF-β1, and IFN-γ (Figs 4 and 5).