PTPN1 and type 2 diabetes mellitus: PTP1B deficient mice are hypersensitive to insulin and present low basal glycemia and insulinemia (Elchebly et al., 1999), and inhibiting PTP1B improves insulin signaling and reverses T2D phenotypes (Malamas et al., 2000; Zinker et al., 2002; Gum et al., 2003; Tamrakar et al., 2014).