John G. Hagen, MD, MBA, FAAP, FASA, is Director of Pediatric Anesthesiology, Director of the Pediatric Regional Anesthesia Program, and Medical Director of Children's Anesthesiology at Memorial Sloan Kettering Cancer Center. Under his leadership, MSK became the first cancer center to achieve Level I Children's Surgery Verification from the American College of Surgeons.

Dr. Hagen is the founder and editor-in-chief of Baby-Blocks.com, the first open-access platform dedicated to pediatric regional anesthesia education, now reaching over 155,000 users across 240 countries and territories with formal partnerships with ESRA and LASRA. He led the first international Delphi consensus on foundational pediatric regional techniques — endorsed by 12 professional societies and published in Regional Anesthesia & Pain Medicine. He shares this work globally as visiting professor, course director, and workshop faculty from São Paulo to Saudi Arabia to Glasgow.