Consortium of Investigators of Modifiers  of  BRCA1/2  (CIMBA):  Maggie Angelakos ,  Judi Maskiell ,  Gillian Dite  and  Helen Tsimiklis ; members of and participants in the New York site of the  Breast Cancer Family Registry ;  National Cancer Institute  and the Office of the Director,  National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the  National Institutes of Health. CONsorzio Studi ITaliani sui Tumori Ereditari Alla Mammella, Italy (CONSIT Team ): Funds from Italian citizens who allocated the "5 × 1,000" share of their tax payment in support of the  Fondazione IRCCS Istituto Nazionale Tumori , according to Italian laws ( Istituto Nazionale dei Tumori (INT ) institutional strategic project "5 × 1,000") (to SM); the  Italian Association for Cancer Research (AIRC)  (to LO);  National Centre for Scientific Research "Demokritos " has been cofinanced by the  European Union (European Social Fund (ESF) ) and Greek national funds through the  "Education and Lifelong Learning" operational program  of the National Strategic Reference Framework (NSRF) - Research Funding Program  of the  General Secretariat for Research and Technology: ARISTEIA ; " Heracleitus II: Investing in knowledge society  through the  European Social Fund "; the DKFZ study was supported by the  Deutsches Krebsforschungszentrum (DKFZ) ;  Epidemiological Study  of  BRCA1  and  BRCA2   Mutation Carriers (EMBRACE)  is supported by  Cancer Research UK  grants  C1287/A10118  and  C1287/A11990 ;  DGE  and FL are supported by a  National Institute for Health Research (NIHR)  grant to the  Biomedical Research Centre , Manchester, UK; the investigators at  The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust  are supported by an  NIHR  grant to the  Biomedical Research Centre at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London ; RE and EB are supported by  Cancer Research UK  grant  C5047/A8385 ;  Kansas University Medical Center : The authors acknowledge support from  The University of Kansas Cancer Center  ( P30 CA168524 ) and the  Kansas Bioscience Authority   Eminent Scholar Program ; AKG was funded by grants  5U01 CA113916  and  R01 CA140323  and by the Chancellors Distinguished Chair in Biomedical Sciences Professorship; The  German Consortium of Hereditary Breast and Ovarian Cancer (GC-HBOC)  is supported by  German Cancer Aid  (grant  109076  (to RKS) and by the  Center for Molecular Medicine Cologne (CMMC) ;  GC-HBOC  is deeply grateful to  Dr Sabine Preisler-Adam  for providing information and samples; the  GEMO Study  was supported by the  Ligue National Contre le Cancer ; the Association "Le cancer du sein, parlons-en!" Award; and the  Canadian Institutes of Health Research for the CIHR Team in Familial Risks of Breast Cancer program ; G-FAST: KDL is supported by  GOA  grant  BOF10/GOA/019  ( Ghent University ) and spearhead financing of  Ghent University Hospital ; the  Gynecologic Oncology Group (GOG)  was supported by  National Cancer Institute  grants to the GOG Administrative Office and  Tissue Bank  (grant  CA 27469 ), the  GOG Statistical and Data Center  (grant CA  37517 ) and  GOG's Cancer Prevention and Control Committee  (grant  CA 101165 ); HCSC was supported by grants  RD12/00369/0006  and  12/00539  from  Instituto de Salud Carlos III (ISCIII) ,  Madrid, Spain , partially supported by  European Regional Development Fund (Fonds européen de développement régional (FEDER) ) funds; the  Helsinki Breast Cancer Study (HEBCS)  was financially supported by the  Helsinki University Central Hospital Research Fund ,  Academy of Finland  ( 266528 ), the  Finnish Cancer Society  and the  Sigrid Juselius Foundation ; HEBON is supported by the  Dutch Cancer Society  grants  NKI1998-1854 ,  NKI2004-3088  and  NKI2007-3756 , the  Netherlands Organization of Scientific Research  grant  NWO 91109024 , the  Pink Ribbon  grant  110005  and  Biobanking and Molecular Resource Infrastructure (BBMRI)  grant  NWO 184.