Recently, our group and others have characterized secretions of GLP-1 and GIP among NGT and T2DM and found that there are no differences among the two groups in Japanese [23, 71–73] or Korean [74, 75], indicating that incretin secretion per se is not involved in the pathogenesis of T2DM in East Asians, similar to the case in Caucasian. Here, GIP is linked to type 2 diabetes mellitus.