GPR39 and Hyperglycemia: Importantly, as we in the present study find that GPR39 overexpression protects against the development of nonfasting hyperglycemia, zinc-sulfate-enriched drinking water has been reported to prevent STZ-induced diabetes in mice [31, 32] and, importantly, to protect against the spontaneous development of diabetes in both NOD mice and biobreeding rats [31, 33].