In particular, several PTPs, including PTPN1, PTPN2, PTPN6, PTPN9, PTPN11, PTPRS, and DUSP9, have been reported to interfere with the insulin signaling pathway and induce insulin resistance in type 2 diabetes, suggesting that PTPs are promising targets for the treatment or prevention of type 2 diabetes [16]. Here, PTPN9 is linked to type 2 diabetes mellitus.