Interestingly, we have also recently shown [39] that loss of the secretory granule zinc transporter ZnT8, encoded by the type 2 diabetes GWAS gene SLC30A8 [5] from the murine alpha cell, leads to exaggerated glucagon release in response to low glucose levels, though alpha cell mass was not altered in the latter model. Here, SLC30A8 is linked to type 2 diabetes mellitus.