These findings are therefore consistent with other studies that non-allergic asthma associated with endotoxin exposure, possibly be due to contamination of dental unit waterlines (56, 67), is mediated by an inflammatory response involving several cytokines, including IL-1, IL-6, IL-8, and TNF-α, IL-12 (25, 68). This evidence concerns the gene CXCL8 and allergic asthma.