1. Case Western Reserve School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
2. Endometriosis CaRe Centre, Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Women's Centre, Oxford OX3 9DU, UK
3. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK
4. Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK