In sporadic breast cancer, the majority of tumours are ER positive (Early Breast Cancer Trialists' Collaborative Group, 1998), whereas the opposite is the case in cancers diagnosed in women with high risk mutations in the BRCA1 and BRCA2 genes (Johannsson et al, 1997; Armes et al, 1999). The gene discussed is BRCA2; the disease is neoplasm.