The major aim of our study was to examine recently described potential association of genes involved in the immune response and inflammation (PTGER4, HLA, TNFSF15, NKX2-3, ZNF365, IFNG, PTPN2, and PSMG1) in adult and pediatric-onset IBD in an Italian population. This evidence concerns the gene TNFSF15 and inflammatory bowel disease.