In this article, we report our findings of pathogenic variants in the 13 established cancer predisposition genes ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, PALB2, PTEN, RAD51C, RAD51D, STK11 and TP53 in a nation-wide cohort of over 4600 women with breast- and/or ovarian cancer. This evidence concerns the gene BRCA1 and cancer.