Yearbook of pediatric endocrinology 2009 : endorsed by the European Society for Paediatric Endocrinology (ESPE) ; the indispensible reference tool The body of knowledge in most medical specialties is rapidly expanding making it virtually impossible to follow all advances in clinical and basic sciences that are relevant to a given field. This is particularly true in pediatric endocrinology at the cross road of pediatrics endocrinology development and genetics. Providing abstracts of articles that report the year’s breakthrough developments in the basic sciences and evidence based new knowledge in clinical research and clinical practice that are relevant to the field the ‘Yearbook of Pediatric Endocrinology 2009’ keeps busy clinicians and scientists pediatric endocrinologists and also pediatricians and endocrinologists informed on new advances.Twelve Associate Editors and their co authors selected from several thousand papers those that brought the most meaningful new information summarized them and provided comments to put them into perspective. The papers are classified into those that identify new genes involved in diseases new hormones concepts revised or re centered important observations for clinical practice large scale clinical trials new mechanisms new paradigms important review articles new fears and new hopes. Because the Yearbook is endorsed by the European Society for Paediatric Endocrinology (ESPE) its publication is linked to the annual meeting of the ESPE. The ‘Yearbook of Pediatric Endocrinology 2009’ covers the medical and scientific literature from June 2008 through May 2009