INS and Hyperglycemia: PB-IPC displayed characteristics of islet β-cell progenitors, including the expression of β-cell-specific insulin gene-associated transcription factors (e.g., MAFA and NKX6.1) and prohormone convertases PC1/3 and PC2, production of insulin, the ability to reduce hyperglycemia, and the ability to migrate into pancreatic islets after transplantation into the streptozotocin (STZ)-induced diabetic mice [24].