BRCA1-associated breast cancers comprise samples with BRCA1 mutations, heterozygous loss, and homozygous deletion (Mann–Whitney U test) (TCGA: BRCA1-associated, N=362; BRCA1-non-associated, N=720; METABRIC: BRCA1-associated, N=540, BRCA1-non-associated, N=1364). This evidence concerns the gene BRCA1 and breast cancer.