WAS and Wiskott-Aldrich syndrome: This interim analysis of data from a study of eight patients with severe Wiskott-Aldrich syndrome, six of whom have been followed up for more than 3 years, suggests that this disease can be successfully treated by one infusion of autologous CD34+ HSPCs transduced with a lentiviral vector encoding for a functional WAS gene, preceded by a reduced-intensity conditioning regimen.