Abstract
Ex vivo cell and gene therapy is a prospective approach to treatment of genetic diseases. To date, one of the most prevalent examples of genetically engineered cell therapies is hematopoietic stem/progenitor cells (HSPCs). This mini review is focused on HSPC therapy methods that have been approved for medical use. Most gene therapy methods rely on the lentiviral integration of the gene into the target cell genome, as lentiviruses are extremely effective, particularly in transduction of non-dividing cells. In this constantly evolving field, it is important to find the balance between safety concerns and efficiency. Analyzing cases of several diseases, for which ex vivo gene therapy was developed, we strive to understand which factors are crucial to success and what the potential drawbacks are. Although in general, viral gene integration demonstrates a considerable therapeutic effect, it has oncogenic potential. Development of self-inactivating vectors was a breakthrough in regard to safety, but the possibility of oncogenesis remains, and strict analysis of integration sites is required.