Jonasson and colleagues showed decreased DSS (HR = 1.61 95% CI 1.11–2.35) in BC patients carrying the Icelandic founder 999del5 BRCA2 mutation, which was even more pronounced in ER-positive patients (HR = 1.92 95% CI 1.20–3.05) [16]. Here, BRCA2 is linked to breast cancer.