BRCA2 and breast cancer: In the present study, given previous evidence of 1) the functional interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 in mammary epithelial polarization [4], and 2) the potential modification of breast cancer risk in BRCA1 mutation carriers by common genetic variation in HMMR [4], we further assessed the association between variants in AURKA-HMMR-TPX2-TUBG1 and breast cancer risk in BRCA1 and BRCA2 mutation carriers.