Schematic representation of gene fusions and the expressed fusion transcripts in the breast cancer cell line ZR75-30 (not to scale). A. Fusions in the 8;17 amplicon. B. Structure of fusion transcripts detected by Robinson et al. . C. Fusions at single copy breaks. Relevant exons are represented as numbered boxes, the transcription start site (AUG) is indicated with a black arrow and the breakpoint is indicated with a zig-zag line at the approximate chromosomal position (based on the UCSC Genome Browser, hg19). The (sequenced) expressed fusion transcripts and (where applicable) alternative splice products are shown below as black boxes joined by a dotted line. Exons depicted in grey are expected to be expressed, but were not sequenced. For numbering of exons see Additional file 1.