a, sgRNAs in the target region of the UMPS gene are shown with their attributed symbol, the genomic target sequence and the specificity score. sgRNAs are ranked by their predicted specificity. b, Numbers of predicted off-target sites as evaluated by COSMID are shown in a stacked bar graph. Grey shades encode the COSMID score as annotated in the legend. Sites with lower scores are predicted to be more relevant (higher chance of endonuclease activity). Y-axis is broken to better illustrate results for sgRNAs with <10 predicted off-target sites.