We therefore excluded the nine cases of ILC in this cohort (seven BRCA2 mutation carriers and two BRCA1 mutation carriers), and repeated the analysis including invasive ductal carcinoma alone, showing that multifocality/multicentricity remained significantly higher in BRCA2 versus BRCA1 mutation carriers when cases of ILC were excluded (p = 0.001). Here, BRCA1 is linked to invasive ductal breast carcinoma.