Figure 4.

Mammary cancers that are deficient in Brca1 and haploinsufficient in chromosome 11 are of basal epithelial origin. Immunostaining of cytokeratins 5 (A), 6 (B), 14 (C, E), and 8 (D, F) using Alexa Fluor 594-conjugated secondary antibodies (red) in mammary cancers from MMTV-Cre Brca1^fl/fl Wap^wt/neo females (A–D) and Her2/neu-overexpressing controls (E, F). The slides were counterstained with DAPI (blue nuclei). Arrows in panels A and E indicate the positive staining of cytokeratins 5 and 14 in normal mammary epithelial cells adjacent to the primary neoplasm. Bar, 100 µm.