Bub1 overexpression promotes spontaneous tumorigenesis. (A) Mouse cohort information. Mice were sacrificed between 12 and 16 mo: the average age of the sacrificed animals is indicated per genotype. (B) Spontaneous tumor incidence of mice of the indicated genotypes. *, P < 0.01 vs. wild-type mice using Fisher’s exact test. Error bars indicate 95% confidence interval. (C) Tumor spectrum of mice of the indicated genotypes. Error bars indicate 95% confidence interval. (D) Histological analysis of selected spontaneous tumors from transgenic mice. Black bar, 100 µm. Red bar, 25 µm. Yellow arrow, neoplastic cell; red arrow, normal cell. (E) Interphase FISH for chromosomes 4 and 7 on single cell suspensions of tumors from Bub1 transgenic mice. Normal tissues from age-matched wild-type mice were used as controls.