Another investigation that sought to evaluate its expression in bronchoalveolar lavage fluid (BAL) and supernatant of lipopolysaccharide-stimulated alveolar macrophages in adults with bronchial asthma revealed a marked decrease of IL-18 and suggested that inherently low levels of IL-18 may be associated with the pathogenesis of asthmatic airway inflammation. Here, IL18 is linked to inflammatory response.