PTPN2 and juvenile idiopathic arthritis: Moreover, considering that PTPN2 gene variants are - similar to IL23R gene variants - associated with a number of autoimmune diseases such as juvenile idiopathic arthritis [24] or type 1 diabetes [17], we also analysed for epistasis between PTPN2 and IL23R. In addition, a very recent study suggests that PTPN2 regulates autophagosome formation in intestinal epithelial cells [25].