Fig. 1

Comprehensive overview: viral and non-viral vectors in gene therapy clinical trials. Genus and family of viruses are reported, according to the International Committee on the taxonomy of viruses (ICTV) system. Information about the genetic material, approximate vector capacity (transgene insertion, etc.), morphology (3D structure) of each vector, are also included. On the chart (right side), the application percentage per vector in gene therapy clinical trials is displayed (based on Ginn and co-workers, 2018, John Wiley and Sons, Journal of Gene Medicine. 2018). Among them, vectors Nos. 2, 4, and 5 (colored purple) are also used in gene therapy clinical trials on β-hemoglobinopathies patients, and among them, lentiviral vectors are the most common (colored light orange row with an asterisk). The asterisk has been used to point out the significance of lentiviral vectors on β-type hemoglobinopathies and in addition, as these types of vectors are linked with Fig. 2, demonstrating their performance in clinical practice