Figure 1

Chromogenic in situ hybridisation and immunohistochemical staining of breast cancer samples. (a) Two copies of the CCND1 gene represents nonamplified patients (i). A copy number of 3 to 8 copies was considered a gain (ii). Amplified tumours often exhibit a very high number of CCND1 gene copies (iii). (b) Low cytoplasmic staining without nuclear cyclin D₁ expression (i). Low cyclin D₁ expression in cytoplasm and low fraction-positive nuclei displaying weak staining intensity of most nuclei (ii). Intermediate cytoplasmic expression and fraction-positive nuclei, with nuclei showing moderate staining intensity (iii). High cytoplasmic and nuclear expression of cyclin D₁, with nuclear fraction > 67% (iv).