In November 2023, the UK's regulator approved the world's first gene therapy for Sickle Cell Disease and Beta-thalassemia. The new therapy utilizes CRISPR technology to disinhibit a gene that produces fetal hemoglobin in bone marrow stem cells. These stem cells are then reinfused into the patient after the ablation of the other bone marrow stem cells, upon which they take up residence in the bone marrow and differentiate into red blood cells that produce fetal hemoglobin. This essentially replaces the faulty HgS and reduces the likelihood of sickling and crises. On December 8th, 2023, the FDA approved the same gene therapy to treat Sickle Cell Disease, along with a second gene therapy that utilizes a lentiviral vector to insert a gene that produces a novel form of HbA into bone marrow stem cells, before reinfusing the bone marrow stem cells. The reinfused stem cells take up residence in the bone marrow of the treated person, where they produce red blood cells containing the novel HbA in place of the faulty HbS that is the underlying cause of the symptoms.