PTPN1 and Hyperglycemia: Furthermore, hyperglycemia up-regulated the expression of PTP1B and inhibited VEGF-induced vascular formation, proliferation, and migration (Zhang et al., 2015), PTP1B activity was significantly elevated in DW, topically applied PTP1B inhibitor may help counterbalance ER stress (Thiebaut et al., 2018) and accelerate DW healing (Zhang et al., 2017; Figueiredo et al., 2020).