Extent and pattern of the HER2 -amplicon on chromosome 17q12-q21 in HER2+ BC. (A) Frequency of amplification across 200 HER2-amplified tumors analyzed by BAC aCGH. Frequency estimates correspond to number of tumors with segmented log2ratio >0.5 for respective BAC probe and are displayed at respective BAC probe's center position (red circles). Shortest region of amplification overlap (SRO) was defined from involved BAC probes genomic start and stop position and is marked with a light gray background. Genomic position of eight BAC probes mapping to the SRO is displayed together with their center position (black circle). (B) Close-up of chr17:35000001-35200000 (hg18 build) for tumor TAX577717 analyzed by zoom-in oligonucleotide aCGH. (C) Close-up of chr17:35000001-35867695 (hg18 build) for tumor TAX577700 analyzed by zoom-in aCGH.