DPP4 and type 2 diabetes mellitus: Saxagliptin, an orally active, highly potent, selective dipeptidyl peptidase-4 (DPP-4) inhibitor [1, 2] was first approved in the United States in 2009 as an adjunct to diet and exercise to improve glycaemic control in adults with T2D at doses of 2.5 or 5 mg once daily [3].