KLF1 and Huntington disease: To evaluate the ability of BEs to target the HBG promoters in repopulating HSCs, we xenotransplanted HD or SCD HSPCs transfected with CBE-SpRY-OPT2 mRNA and LRF_bs_2 sgRNA (LRF 8C) or with ABEmax mRNA and KLF1_bs_1 sgRNA (KLF1) into immunodeficient NBSGW mice (Fig. 8a).