Off-target distribution analysis of CRISPR target sites in HBB gene. (a) Statistics of off-target sites located in exons, transcriptional factor binding sites (TFBS), or noncoding DNA (ncDNA). The box plots depict 10th, 25th, 50th, 75th, and 90th percentiles of the candidate sites. The diamond points in the boxes indicate the average off-target numbers. The scatter plots show relevant off-target numbers of each candidate site. (b) Identification of conserved NF-YA binding sites in off-target sites #3–#9 of the candidate site I1-1.