IFNG and inflammatory bowel disease: The serum levels of IL-17a, sCD40L, Platelet-derived Growth Factor-AA, Macrophage-Derived Chemokine (MDC), and IFNγ were lower in patients with IBD than in the healthy control patients, suggesting a unidirectional flow of cytokines toward the site of the inflammation.18 However, none of the cytokines differed significantly in concentration between the patients with UC and patients with CD.