Loss of functional variants in the PTPN2 gene encoding T cell tyrosine phosphatase (TCPTP) is connected with an increasing risk of chronic inflammatory diseases, including rheumatoid arthritis (32) and type I diabetes (33), Celiac disease and IBD, ulcerative colitis, and Crohn’s disease (33, 34). The gene discussed is PTPN2; the disease is Crohn disease.