β cell proliferation was monitored during the experimental period outlined; n=4 mice/time point. (A–F) Labeling for insulin (Ins, blue), Ki67 (red), and CD31 (green). Scale bar is 50 μm and applies to A–F. (G) Quantification of β cell proliferation. ##, p<0.01, 1wk Dox vs. No Dox, 1wk WD, 2wk WD, or 3wk WD. **, p<0.01, 1wk WD or 2wk WD vs. No Dox, 1wk Dox, 3wk WD, or 6wk WD. No Dox, 1wk Dox, 3wk WD, and 6wk WD comparisons were not statistically significant. (H–K) Increased β cell proliferation was not associated with increased Bmi–1; insulin (Ins, green), Bmi-1 (red), Dapi (blue). Scale bar is 25 μm and applies to H–K.