FOXO1 and Hyperglycemia: It has been shown in rat and mouse studies that stressors such as pancreatectomy induced hyperglycemia (78), loss of FoxO1 expression combined with multiparity or aging (79) and hyperglycemia induced by the ectopic expression of an activated KATP channel (80, 81) resulted in β cell dedifferentiation marked by loss of expression of β cell identity genes, degranulation and upregulation of disallowed genes.