...stranded breaks. Cytosine base editors are created by fusing Cas9 nickase or catalytically inactive “dead” Cas9...cytosine base editors, the evolved TadA domain is fused to a Cas9 protein to create the adenine base editor...have been made by optimizing expression of the fusions, modifying the linker region between Cas variant...deaminase to adjust the editing window, or adding fusions that increase product purity such as the DNA glycosylase... from the Michael Bassik lab , in which Cas9 is fused to activation-induced cytidine deaminase (AID). ...