STAT3 and Hyperglycemia: While diabetes is a complex disease, and STAT3 can be phosphorylated by many cytokines that utilize the gp130 receptor [45], it appears that hyperglycemia (but not hyperosmolarity) is sufficient to increase IL-6-induced STAT3 phosphorylation in keratinocytes in vitro (Figures 4(b) and 4(c)).