BRCA1, BRCA2, and MLH1 protein expression in paired primary and recurrent neoplasms. Protein expression is represented by brown stain. Black bars in the lower left corners are equal to 10 microns. A. BRCA1 expression is low in the primary neoplasm. B. BRCA1 expression is increased in the paired recurrent neoplasm. C. BRCA2 protein expression is low in a different primary neoplasm. D. BRCA2 expression is increased in the paired recurrent neoplasm. E. MLH1 protein is normal in a different primary neoplasm. F. In the paired recurrent neoplasm, MLH1 protein expression is reduced.