Bruce Chabner is a professor of medicine at Harvard Medical School and clinical director emeritus of the Massachusetts General Hospital Cancer Center. Stephen Morrissey, the interviewer, is the Executive Managing Editor of the Journal. I.D. Goldman and B.A. Chabner. Cerebral Folate Deficiency, Autism, and the Role of Leucovorin. N Engl J Med 2026;394:833-835.