In Memoriam: John B. Mulliken, MD It is with profound sadness that we share the passing of John Butler Mulliken, MD, on January 20, at the age of 87. To say that Dr. Mulliken was a giant in plastic and reconstructive surgery would be an understatement. He was a visionary whose groundbreaking work transformed countless lives and shaped the very foundations of how we understand and treat vascular anomalies and craniofacial conditions.

For more than five decades, Boston Children's was Dr. Mulliken's professional home. He joined us in 1974 as the first associate of the legendary Nobel laureate, Dr. Joseph E. Murray. Over the years, he built programs that became beacons of hope for families worldwide. As Co-Director of our interdisciplinary Vascular Anomalies Center, Director of the Craniofacial Center, and Director of the Cleft Lip and Palate Program, Dr. Mulliken innovated, collaborated across disciplines, and cared deeply for every patient who walked through our doors.

Dr. Mulliken's contributions to medicine are extraordinary. His development of the Mulliken classification system for vascular anomalies revolutionized how clinicians worldwide diagnose and treat these complex conditions, bringing clarity to a previously confusing field and establishing it as the international standard. His collaboration with molecular geneticists uncovered the genes responsible for several inherited vascular conditions, opening new treatment pathways and providing answers that families desperately needed.

His pioneering single-stage approach to bilateral cleft lip repair earned him the prestigious James Barrett Brown Prize in 1996. With exacting attention to detail, he developed techniques that emphasized both functional and aesthetic outcomes. But what mattered most to Dr. Mulliken was the result: children who could smile with confidence, and families who could look forward with hope. In 1986, together with the families of many of his patients, he co-founded the Foundation for Faces of Children, a non-profit dedicated to providing educational resources to children born with craniofacial differences and their families.

For all his remarkable achievements, those who knew Dr. Mulliken will remember him best for his humanity. He was an extraordinary mentor who trained hundreds of surgeons, instilling in them not just technical excellence but deep empathy and unwavering commitment to advancing care through research. He received Harvard Medical School's William Silen Lifetime Achievement in Mentoring Award and the Clinician of the Year Award from the American Academy of Pediatrics. Many of his mentees have become leaders in their own right, carrying forward his legacy.

Dr. Mulliken's legacy lives on in every child whose life he transformed, every surgeon he inspired, and every scientific advancement he championed. Boston Children's, and the world, have lost a true legend and we will honor him by continuing the work he loved so passionately.