High tumour CIN% was correlated (Pearson’s χ2) with high pathological grade (P=0.008), HER2 amplification (P=2.89e-5), and Ch17CEP duplication (P=3.68e-7) but was not associated with size, nodal status, ER or proliferation (measured by Ki67; Supplementary Table S1). The gene discussed is ERBB2; the disease is neoplasm.