5-IT effects on endogenous mouse pancreas. A: Immunohistochemistry for proliferating β-cells in pancreatic sections of human islet graft–bearing mice showing insulin (red), BrdU (green), and DAPI (blue). Magnified images (×40) mark proliferating β-cells from 10× merged samples. Representative experiment from n = 4. B: Quantification of proliferating β-cells for BrdU/insulin. Error bars indicate ±SEM. P values were determined by unpaired Student t test. *P < 0.05. HI, human islet; HI Tx, vehicle treated; HI Tx + 5IT, 5-IT treated.