In the prior years of the grant, the Gene Transfer and Gene Therapy ore (GTAGTC) has produce retroviral vectors for the investigators of the projects. We have gained proficiency in the design, construction and packaging of HIV-1 based lentiviral vectors. The Core has also supported clinical gene therapy trials for Gaucher disease and ADA-deficient SCID. In the next funding period, the GTAGT Core will use current state-of-the- art vectors and packaging system to design, construct, package and perform initial characterization of retroviral and lentiviral vectors for investigators of the Projects to pursue their scientific objectives. Additionally, the Core will continue to perform transductions of patient HSC for clinical gene marking and gene therapy studies and molecular analyses of samples from clinical gene therapy trials to define the extents of gene transfer and expression.