Analysis of the CEP17 signal in tumor samples from evaluable patients showed that polysomy (defined as ≥3 CEP17 signals) occurred in only 23/567 (4.1 %) of cases in patients randomized and enrolled into ToGA with HER2-overexpressing or gene amplification status and in 133/3,317 (4.0 %) of the entire screening population. The gene discussed is ERBB2; the disease is neoplasm.