Fig A1.

Immunohistochemistry performed on human breast tissue by using the C-terminal BRCA2 antibody provided by EMD Chemicals (Gibbstown, NJ). The red color represents specific staining of the antibody peroxidase reaction, and the yellow color represents a neutral counter stain, Metanil Yellow. Left panels are ×20, and right panels ×100, magnification. Tissue sections show BRCA2 hereditary cancer (upper panels); normal breast from patient with BRCA2 hereditary cancer (middle panels); and sporadic cancer (lower panels). The absence of staining in the hereditary cancer sections (upper right and left panels) are caused by the 6174delT truncation mutant in this patient.