1. Division of Systems Medicine, Department of Pediatrics, Stanford University School of Medicine, 251 Campus Drive, Stanford, CA 94305–5415, USA.
2. Training Program in Biomedical Informatics, Stanford University School of Medicine, Stanford, CA 94305–5479, USA.
3. Lucile Packard Children’s Hospital, 725 Welch Road, Palo Alto, CA 94304, USA.
4. Division of Gastroenterology, Department of Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305–5187, USA.
5. Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305–5324, USA.