These tumour characteristics are partly determined by germ-line mutations, as exemplified by BRCA1 mutations which are frequently associated with triple-negative breast cancers, but breast cancer pathology also seems to be influenced by low-penetrance variants like those in FGFR2 that are strongly correlated with estrogen-receptor positive disease [95,96,151]. The gene discussed is BRCA1; the disease is triple-negative breast carcinoma.