Using this approach, we implicate causal genes at six loci associated with fasting glucose and/or FI (G6PC2, GPSM1, SLC2A2, SLC30A8, RREB1 and COBLL1) and five with T2D (ARAP1, GIPR, KCNJ11, SLC30A8 and WFS1). This evidence concerns the gene RREB1 and type 2 diabetes mellitus.