" BRCA2 are so-called caretaker genes, cancer-suppressing genes responsible for DNA repair. Mutations in this gene can cause a rare form of hereditary breast cancer. As has been well publicized, Angelina Jolie decided to undergo a preventive double mastectomy. A National Breast Cancer Coalition survey found that the majority of women believe that most breast cancers occur among women with a family history or a genetic predisposition to the disease.141 The reality is that as few as 2.5 percent of breast cancer cases are attributable to breast cancer "

― Michael Greger , How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease