Khaled M Musallam1, Stefano Rivella2, Ali T Taher3. 1. International Network of Hematology, London, UK. 2. Department of Pediatrics, Division of Hematology; Raymond G. Perelman Center for Cellular and Molecular Therapeutics; Abramson Research Center at The Children's Hospital of Philadelphia (CHOP); Cell and Molecular Biology Affinity Group (CAMB), Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA. 3. Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.