IL33 and pulmonary emphysema: However, CS-induced pulmonary inflammation was largely improved in SphK2−/− mice, both the CD45+CD11b+ subpopulation and the production of IL-6 and IL-33 decreased, indicating that SphK2 deficiency attenuated pulmonary inflammation and small airways fibrosis, and delayed emphysema pathogenesis possibly by reducing S1P production, blunting the S1P signaling and preserving the pulmonary CFTR function.