Although we did not find off-target effects at the top 10 potential off-target sites examined, the specificity of base editors needs more comprehensive investigation through genome-wide specificity assays, such as Digenome-seq (Kim et al., 2017a). Indeed, additional genome-wide specificity assays are sorely needed for in-depth and accurate investigation of the in vivo specificity of base editors. Furthermore, the precision of base editors should be further improved to eliminate base conversion at G−25. Whether base editor variants such as YE1-BE3, YE2-BE3, EE-BE3, and YEE-BE3 will prove more appropriate warrants further investigation.