Significant differences in interferon (IFN)-α, IFN-γ, IL-10, IL-12P70, IL-2, IL-4, IL-5, IL-6, IL-8, TNF-α, and IL-1β were found among the AS, RA, and HC groups (P < .001); however, no significant difference was noted in IL-17A levels. This evidence concerns the gene CXCL8 and rheumatoid arthritis.