Examples of chromosome 18 aCGH profiles. (A) Tumor T13708 on the left does not present any gene copy number aberration. Tumors T6165, T8581, T11305, T8295, T9193, T6744 and T8700 exhibit copy number losses on the short arm of chromosome 18. The genomic profile observed in tumor T8700 shows the smallest region targeted by the 18p loss. (B) The smallest deletion observed in breast primary tumor T8700 targets the L3MBTL4 gene (18p11.31) and includes the minimal 18p common lost region, Chr18:6,366,938-6,375,929 bp defined with 96% of studied tumors (Additional file 1, Table S4A). ( C, D) Breakpoint targeting the L3MBTL4 gene in breast primary tumor T50115 and HCC38 breast cancer cell line.