IL18R1 and pulmonary fibrosis: However, a subsequent study by Hoshino et al. demonstrated that IL-18 and IL-18Rα are elevated in the lungs of patients with bleomycin-induced lethal lung injury and in the lungs of mice following bleomycin challenge and that IL-18- and IL-18Rα-deficient mice are protected from bleomycin-induced lung fibrosis, suggesting a pro-fibrotic role for IL-18 [173].