The product distribution among edited DNA sequencing reads (reads in which the target C is base edited) is shown for each CBEmax variant with no UGI (“CBEmax-B” variants) tested at the same two sites as in Fig. 2g. Subscripted numbers indicate protospacer positions, counting the first base of the PAM as position 21. Values and error bars reflect the mean ± s.d. of three biological replicates performed on different days at each site. ns, P > 0.05; *P < 0.05; **P < 0.01; ***P < 0.001, by two tailed Student’s t-test.