Crystal L. Mackall (born August 21, 1960) is an American physician and immunologist. She is currently the Ernest and Amelia Gallo Family Professor of Pediatrics and Medicine at Stanford University. She is the founding director of the Stanford Center for Cancer Cell Therapy. Education and early career Mackall grew up in East Palestine, Ohio in a working-class family; her father was a steelworker. She received her medical training through a six-year BS/MD program, earning her bachelor's degree at the University of Akron and graduated summa cum laude. She completed her medical education at Northeast Ohio Medical University, earning her Doctor of Medicine in 1984. She was a member of the Alpha Omega Alpha honour society. Mackall completed an internal medicine and pediatrics Residency at Cleveland Clinic Akron General and Children's Hospital of Akron in 1988. In 1989, Mackall joined the National Cancer Institute as a fellow in pediatric oncology, where she began to focus on immunotherapy for cancer. She remained at National Institutes of Health until 2016, eventually serving as the Chief of the Pediatric Oncology Branch. She moved to the Stanford University School of Medicine in 2016. She is Board Certified in Internal Medicine, Pediatrics, and Pediatric Hematology/Oncology. Research Mackall has pioneered cancer immunotherapies for children. Her early research defined the effects of traditional cancer therapies on the immune system, where she identified the role of the thymus in human T cell regeneration and discovered that Interleukin-7 (IL-7) is the main regulator of T cell homeostasis in humans. Her group was among the first to demonstrate impressive activity of CD19 chimeric antigen receptor (CAR T cells) therapies for childhood leukemia and also developed a CAR targeting CD22 that is active in this disease and has received Breakthrough Therapy Designation from the US FDA for treatment of CAR19 refractory B-ALL. The CD22-CAR developed by Mackall's team is also active in large B cell lymphoma and has received Breakthrough Therapy Designation from the US FDA for this indication. Working with the Monje lab at Stanford, Mackall developed a GD2-CAR that showed activity in preclinical models of diffuse midline glioma, which are lethal brain tumor occurring primarily in children and young adults, and her group demonstrated that intracerebroventricular delivery of CAR T cells is more potent for treatment of brain tumors in mice than intravenous delivery. Mackall and Monje are leading a clinical trial of GD2-CAR for diffuse midline gliomas, given intravenously