BRCA1 and cancer: Genetic testing for inherited cancer susceptibility is an established part of care for individuals in whom family histories or ancestry indicate significant liability to cancer in many health care systems.1 For example, genetic data can be used to inform the future risk of disease as part of cancer screening programs in populations that are influenced by particular founder effects, such as screening interventions directed at identifying BRCA1/BRCA2 breast and ovarian cancer susceptibility variants among Ashkenazi Jews.2