Data from our laboratory on patients with invasive breast cancer, randomised to either tamoxifen or no adjuvant therapy after surgery, also support the theory that cyclin D1 overexpression is associated with an impaired prognosis in antioestrogen-treated patients, but in contrast associated with a more favourable outcome in untreated patients (to be published). The gene discussed is CCND1; the disease is invasive breast carcinoma.