Recently, deficiencies of interleukin-10 (IL-10) and IL-10 receptor (IL-10R), leading to defective STAT3 dimerization, have been shown to cause severe dysregulation of the immune system, resulting in VEO-IBD with perianal disease and the key to an effective therapy lies in early diagnosis and successful hematopoietic stem cell transplantation (HSCT) in these patients [2, 5]. This evidence concerns the gene IL10 and inflammatory bowel disease.