Fig. 4.

Higher grade and less differentiated 4.1B^−/−;TRAMP prostate carcinomas likely arise from tumorigenic lesions that exhibit less apoptosis than those of heterozygous lesions. (A) Each entire prostate was assigned a single highest grade identical to the highest grade assigned to any one constituent lobe. Please refer to SI Fig. 14 for additional histologic scoring results organized by prostate lobe. (B) Proliferation rates were similar regardless of 4.1B status in 22-week-old, grade 4 TRAMP ventral prostates, but 4.1B^−/− TRAMP ventral prostates were significantly less apoptotic relative to grade- and age-matched 4.1B^+/− TRAMP prostates (C). (D) Representative sections stained for apoptotic cells.