The γ-globin gene promoter (HBG2; hg-19 chr11:5,276,109-5,276,225, HBG1; hg19-chr11:5,271,185-5,271,301) showing variants that cause HPFH by creating new binding motifs for the transcriptional activators KLF1, TAL1 or GATA1. Promoter binding motifs for the transcriptional repressors ZBTB7A and BCL11A are highlighted in orange and yellow, respectively. sgRNA spacer sequences used to install each variant with ABEs are represented as black bars, and PAMs are represented as green bars. On-target edits and potential bystander edits are in blue and red fonts, respectively, and are numbered from the 5′ end of the protospacer. Healthy donor human CD34 + HSPCs were electroporated with RNP complexes consisting of ABE7.10 complexed with sgRNA –198, ABE7.10-NG complexed with sgRNA –175 or ABE7.10 complexed with sgRNA –113. Alternatively, cells were electroporated with Cas9 complexed with sgRNA targeting the AAVS1 site, the γ-globin promoter BCL11A binding motif or the BCL11A gene erythroid enhancer. Negative controls included UT cells or cells transfected with ABE7.10 complexed with NT sgRNA. Electroporated cells were induced to undergo erythroid differentiation.