Cytokine analysis revealed that moderate-to-severe OSA was associated with a mixed Th1/Th2 inflammatory axis involving IL-6, TNF-α, IFN-γ, IL-13, CCL2, CXCL1, and IL-4, while mild OSA was associated with innate activation and chemotaxis (IL-1β, IL-18, CXCL10, GM-CSF). This evidence concerns the gene IL18 and obstructive sleep apnea syndrome.