Systems biology and pediatric research: Parviz Minoo, PhD, Olaf Wolkenhauer, PhD, and Susan Guttentag, MD, are the Guest Editors for this annual review issue on systems-based pediatric research. Dr Minoo is a Hastings Professor of Pediatrics and Director of Research at the University of Southern California Keck School of Medicine in Los Angeles. Dr Wolkenhauer is Professor of Systems Biology and Bioinformatics at the University of Rostock, Germany. Dr Guttentag is an Associate Professor for Pediatrics in Neonatology at the Perelman School of Medicine of the University of Pennsylvania and the Children’s Hospital of Philadelphia.