TNF and inflammatory bowel disease: In pediatric IBD patients, serum levels of cytokines and chemokines (IL-1β, IL-4, IL-6, IL-13, TNF, IL-1ra, IL-5, IL-7, IL-12, IL-8, CCL11, and CCL4) are increased and IL-7 was identified as a candidate biomarker for distinguishing CD from UC [73].