The Therapeutic Development Branch (TDB) in the Division of Preclinical Innovation (DPI) of NCATS advances novel therapeutics and technologies through preclinical and clinical stages of development. TDB initiated NCATS’ collaborative Rare Disease Platform Vector Gene Therapy (PaVe-GT) program. The program involves preclinical development and clinical evaluation of gene therapy products for rare diseases. In-silico and Ex-vivo analysis of the candidates is essential in de-risking the potential failure of the candidate in human subjects.