1. Department of Pediatrics, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, Wisconsin, USA
2. Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, USA
3. Department of Medicine, Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
4. Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA