Pancreatic histopathology of E2F1/E2F2 double homozygotes. Pancreas sections obtained from E2F-deficient and WT animals stained with H&E. (A and B) Representative pancreas section of 7-day-old (A) and 2-month-old (B) WT male mice. Magnification, ∞600. (C and D) Representative pancreas section of 2-month-old (C) and 6-month-old (D) E2F1-deficient male mice showing aberrantly large nuclei (marked with arrowheads). Magnification, ∞600. (E_G) Representative pancreas section of 7-day-old (E) and 2-month-old (F and G) DKO male mice. (E and F) Magnification, ∞600. (G) Magnification, ∞400. The acini and islets (marked with an asterisk) in the DKO pancreas are abnormal and have lost their typical tubular organization, which has been replaced by ductal structures. Note the dysplasic changes in acinar cells, characterized by hypertrophy and karyomegaly. (H) Representative pancreas section of a 2-month-old E2F2-deficient male mouse. Magnification, ∞600. The morphology of the pancreas in female E2F-deficient mice was essentially the same as the morphology of the pancreas in male counterparts (data not shown). The sections shown are representative examples from histology for six WT (n = 3 male, n = 3 female), 15 DKO (n = 8 male, n = 7 female), six E2F1^_/_ (n = 3 male, n = 3 female), and six E2F2^_/_ (n = 3 male, n = 3 female) mice.