title: Gene therapy: two steps forward, one step back.
authors.forename: Josephine
authors.initials: J
authors.lastname: Johnston
authors.forename: Francoise
authors.initials: F
authors.lastname: Baylis
mesh_terms: D016026:Bone Marrow Transplantation; D002648:Child; D015316:Genetic Therapy / Q000009:adverse effects*; D006801:Humans; D007938:Leukemia / Q000209:etiology*; D008297:Male; D016254:Mutagenesis, Insertional; D010297:Paris; D016511:Severe Combined Immunodeficiency / Q000628:therapy*