INS and Hyperglycemia: Although at the time point post-tamoxifen used in this study (8 days) a significant increase in fasting blood glucose was apparent (Fig. 2), the alterations in insulin and glucagon expression observed after Pax6 deletion were markedly different in both extent (insulin) and direction (glucagon) from those reported previously in response to hyperglycemia induced by KATP channel activation in β cells (49).