a, Schema for cerulein-induced pancreatitis. b, Immunohistochemistry for Tomato in Ptf1aCreER; Kras mice and TertCreER; Kras mice one month after cerulein-induced pancreatitis (AP). c, Quantification of number of clones per 20x high-power field (HPF) in Ptf1aCreER; Kras mice (n=7) and TertCreER; Kras mice (n=7) one month after cerulein-induced pancreatitis (AP) (mean ± SD). d, e, Representative metaplastic area (d, dashed line) and PanIN lesion (e, black arrow) in H&E staining of TertCreER; Kras mice one-month post injury (AP) (n=9 mice). f, g, Representative H&E staining (f) and Immunohistochemistry for Tomato (g) of Ptf1aCreER; Krasmice one-month post injury (AP) with high dose tamoxifen (5mg) (n=9 mice). h–k, Immunofluorescence analysis of a TertCreER (h, i) and TertCreER; Kras (j, k) mice one month after sham (h, j) or cerulein (i, k) treatment. Acinar cell expansion (red arrows) and PanINs (white arrow) are shown. Scale bar 100µm (a, c–f) and 50µm (g–j).