“…29–50 Setting of these thresholds is complicated not only by genomic heterogeneity and proliferative activity of tumours, but also by the substantial nuclear truncation resulting from tissue sectioning. Control specimens used to set these thresholds have included human lymphocytes,29,31,33,50 cholangiocarcinoma cell-line controls,31,51,52 benign breast-lesions or biopsies (eg, fibroadenomas, sclerosing adenosis),38,53 healthy breast tissue,30,32,36,40,54,55 and paired healthy breast tissue 36. Typically, 5–30% of cells displayed monosomy and less than 5% displayed polysomy in healthy (control) epithelium 10,56–58…”