Fig. 2.

In vivo and ex vivo gene therapy. In both methods, the therapeutic gene is inserted into viral vectors. With in vivo GT, represented on the left of the image, the vectors can be administered through intra-parenchymal or systemic routes. In ex vivo GT (on the right), patient’s cells are collected and stem cells are isolated, which are later mixed with the viral vector. The final transduced stem cells are later re-infused in the patient, restoring the healthy phenotype