In ERpHER2p tumors the most recurrent regions overlapped with or were in close proximity to typical sites of recurrent amplification in breast cancer such as 8p12, 8q24, 11q13, 20q13.2 (ZNF217), 17q12 (including ERBB2), 17q22, but also small regions on 5q31.1-q31.2 (e.g., BRD8, CDC23), 1p21.1-p13.3, and 1p36.21 (see Supplementary Table 1 for details and gene lists). This evidence concerns the gene CDC23 and breast cancer.