In a previous study on 863 primary operable invasive ductal carcinomas with long-term follow-up (Rudolph et al, 1999a), of which only a minor proportion had been treated with Topo IIα inhibitors, high Topo IIα expression consequently emerged as an important independent predictor of adverse outcome next to nodal metastasis and before other classical or immunohistochemical factors, including Ki-67. The gene discussed is MKI67; the disease is invasive ductal breast carcinoma.