aAflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, and Emory University, Atlanta, GA

bClinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington

cDepartment of Pediatrics, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington

dPediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA

Correspondence to Nirali N. Shah, MD, MHSc, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Tel: +240 760 6199; e-mail: [email protected]