The EDIT‐301 hematopoietic stem and progenitor cells (HSPCs) developed by Editas Medicine transplanted into patients have been edited using Cas12a to target the HBG1 and HBG2 gene promoters, upregulating the production of hemoglobin F, which can replace the faulty adult hemoglobin produced by sickle cell disease patients. Here, HBG1 is linked to sickle cell disease.