PTPN1 and Hyperglycemia: The reduced phosphorylation of p38 MAPK is associated with improvements in hyperglycaemia and hyperinsulinaemia in the diabetic ob/ob mice after treatment with an antisense oligonucleotide against protein tyrosine phosphatase 1B (PTP1B) that plays a crucial role in the effect of glutathione depletion on lipid metabolism [41,42].