Among these, the most common types are represented by Breast Cancer (BC) and Ovarian Cancer (OC) due to mutations of the BRCA1 and BRCA2 genes, Familial adenomatous polyposis (FAP) due to mutations of the APC gene, and Hereditary Nonpolyposis Colorectal Cancer (HNPCC) due to mutations of the genes involved in the mismatch repair. The gene discussed is BRCA2; the disease is breast cancer.