The promise of genome editing technologies (GETs) for gene therapy is one of the key drivers for development of this field to treat monogenic hereditary diseases. However, the general consensus of research community and many physicians is that in some cases the balance of risk and benefit of GET-based drugs and CRISPR/Cas9, in particular, has not been fully studied to date. However, on December 03, 2023, the US Food and Drug Administration (FDA) approved marketing of two products for sickle cell disease. One of them (“Casgevy”) is a cellular product consisting of CD34+ autologous hematopoietic stem cells, in which, using the CRISPR/Cas9 system, it was possible to increase the production of fetal hemoglobin, which leads to compensation of patient’s condition. Thus, for the first time in world practice, national regulator has approved not just a genetically modified cell product, but a product obtained using GET. This short message is dedicated to this historical event and its importance, as well as possible consequences.