BRCA2 and breast neoplasm: In the multivariate analysis, there was no observed reduction in mortality in BRCA2 mutation carriers with ER-positive breast tumours associated with the use of tamoxifen (HR = 0.91; 95% CI 0.49–1.69, p = 0.76) (Fig. 3a) or with chemotherapy (HR = 1.03; 95% CI 0.51–2.06, p = 0.94) (Fig. 3b).