Methods: PubMed, Google Scholar, Scopus, and CENTRAL databases were searched through keywords; inflammatory bowel diseases, Crohn’s disease, ulcerative colitis, biosimilar and child were combined using “AND” and “OR.” Original research articles involving pediatric patients receiving one of the biosimilar medications based on the anti-TNF-α biologic drugs approved for pediatric IBD treatment, independently from efficacy and drug response, were included. The gene discussed is TNF; the disease is ulcerative colitis.