To illustrate the application of mouse genetics in going “from mice to humans” we will now consider 4 genes from human diabetes GWAS examined in recent studies; FTO, TCF7L2, CDKAL1, and SLC30A8 (Fig. 1), all of which had not previously been considered as prominent candidates for diabetes research until uncovered by GWAS. The gene discussed is SLC30A8; the disease is diabetes mellitus.