World Federation of Hemophilia Gene Therapy Registry. Issue 4 (27th May 2020) - Konkle, Barbara A.; Coffin, Donna; Pierce, Glenn F.; Clark, Cary; George, Lindsey; Iorio, Alfonso; Mahlangu, Johnny; Naccache, Mayss; O'Mahony, Brian; Peyvandi, Flora; Pipe, Steve; Quartel, Adrian; et al.