SCD and Schnyder corneal dystrophy: Studies further developed a therapeutic cell product (gcHBB‐SCD) for HBB correction in HSPCs using ex vivo Cas9‐RNP and rAAV6 to achieve up to 34% HBB allele correction in HSPCs from donor patients with SCD without abnormal hematopoiesis, genotoxicity, or tumorigenicity.226