Doctors at Great Ormond Street Hospital/ UCL Institute of Child Health report that five patients with x-CGD have responded to gene therapy, showing clear clinical benefit. Patients saw a clear but temporary improvement in their immune system, which helped with their serious illness at the time. However, the correction of the gene defect is not permanent. This is the third immune disease which has responded to gene therapy at GOSH and demonstrates the continued potential of research into this treatment technology. The work was funded by the NIHR Biomedical Research Centre at Great Ormond Street Hospital, AFM, GOSHCC, The Chronic Granulomatous Disorder Society, Wellcome Trust, and the MRC.