It has been reported that genes responsible for primary immunodeficiency diseases (PID), including interleukin-10 (IL-10) or IL-10 receptor (IL-10R) deficiency, X-linked inhibitor of apoptosis (XIAP) deficiency, immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, Wiskott–Aldrich syndrome (WAS), chronic granulomatous disease (CGD), and common variable immunodeficiency, are involved in the molecular pathogenesis of pediatric IBD (5–7). This evidence concerns the gene XIAP and common variable immunodeficiency.