Particularly, variants within the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) are strongly associated with increased risk for developing IBD, but also many other autoimmune/inflammatory diseases such as rheumatoid arthritis (RA) or type I diabetes (T1D) [4,5,21]. This evidence concerns the gene PTPN2 and rheumatoid arthritis.