Fig. 1

Representative images of HER2-negative and HER2-positive breast cancer specimen. a Tumor sections were subjected to IHC using HER2 specific antibodies and were counterstained for nuclei using haematoxylin (blue). Brown colour indicates subcellular localization of HER2. b Determination of HER2 amplification by FISH. Specific probes for HER2 (green) TOP2A (orange) and CEP-17 (blue) were used. The nuclei were selectively stained with DAPI