Based on the results presented above we selected two cell lines to represent the majority of BC patients likely to be candidates for Top1 targeted therapy, namely the MDA-MB-231 and the MCF-7 cell lines, which represent cell lines with TOP1 CN gain (Additional file 1: Figure S1a,d) and estrogen receptor/HER2 negative or positive cells, respectively. The gene discussed is ESR1; the disease is breast cancer.