BRCA1 and neoplasm: Cyclin B1 expression among BRCA2-related tumours did not significantly differ from expression among tumours of sporadic or familial non-BRCA1/2 patients but tumours of sporadic patients showed more often cyclin B1 expression above 10% than tumours of familial non-BRCA1/2 patients (OR 1.7, 95% CI 1.1–2.7, P=0.02).