PCK2 and Insulin resistance: However, P4 can increase blood glucose via gluconeogenesis in parallel with increases in Pgrmc1 expression, a novel membrane receptor for P4, and by increases in the key enzyme mediator of gluconeogenesis, phosphoenolpyruvate carboxykinase (PEPCK), in mice under conditions of insulin deficiency and insulin resistance, which may exacerbate hyperglycemia in diabetes, where insulin action is limited [51].