SYTL4 and type 2 diabetes mellitus: In contrast, genes encoding proteins participating in granule trafficking and membrane exocytosis such as Vamp2, Sytl4, Gjd2 were significantly decreased (Fig. 3d), as was the type 2 diabetes-associated gene Slc30a8, encoding zinc transporter-8 (ZnT8), which is important for insulin secretion32 (Fig. 3d).