ADA and infection: The largest report to date by Cicalese et al. of 18 ADA-SCID patients treated with GT, with a median follow-up of 6.9 years, reported 100% survival with no leukemic transformations, reduced rate of infections and robust T-lymphocyte and later B- lymphocyte reconstitution, although the percentage of gene-corrected myeloid cells was much lower [44].