Similarly, we engineered CGBEWT with St1Cas9evolve to construct the CGBEevolve system (Fig. ). We comprehensively characterized CGBEevolve by testing the editing efficiencies of 29 endogenous genomic sites. Interestingly, only the Cs within the window from positions 5 to 8 could be edited with the CGBEevolve system (Fig. ) although the same Cas9 protein and deaminase were used for CGBEevolve and CTBEevolve. Moreover, only Cs with the TC motif could be edited even if they were located within the editing window from positions 5 to 8 (Fig. ).