WAS and Wiskott-Aldrich syndrome: In the first stem-cell gene therapy for WAS patients conducted in Germany (German Clinical Trials Register number, DRKS00000330) [97, 98], ten patients were treated with autologous CD34+ HSPC modified with an MLV-derived LTR-driven gammaretroviral vector (CMMP backbone—a derivative of MFG pseudotyped with GALV) engineered to express WASP.