In addition we found that the four tumour genomes shared a region of copy number loss/LOH at 6q23.3-q27, which contains ESR1 encoding the ER, as well as a region of copy number loss at 19p13.3-p13.2 measuring 7.9 Mbp (Fig. 3a) and containing 256 genes (Table 3). This evidence concerns the gene ESR1 and neoplasm.