BRCA1 and breast cancer: It is estimated that 5–10% of breast cancers and approximately 25% of ovarian cancers are due to inherited germline mutations in HBOC-related genes that include BRCA1, BRCA2, PALB2, PTEN, RAD51C, RAD51D, ATM, CHEK2, BARD1, BRIP1, CDH1, NBN or TP53 among others.