BLM-induced pulmonary fibrosis involves lung inflammation and injury [25], and thus there is no surprise that the levels of the same pro-inflammatory cytokines such as IL-4 and IL-13 are altered in Scgb1a1-null and Scgb3a2-null mice in both the OVA-induced allergic airway inflammation and the BLM-induced pulmonary fibrosis models [15,24]. Here, IL4 is linked to pulmonary fibrosis.