A new study used directed evolution and extended guide RNAs to produce adenine base editors (ABEs) with improved targeting precision and reduced bystander editing. The team combined enzyme optimization with guide-RNA engineering and validated the improved editors in cellular assays, demonstrating narrower edit windows and fewer unintended adenine conversions. The work provides a practical engineering pathway for developers planning clinical ABE applications and highlights the continuing role of protein evolution plus guide design to close gaps in base-edit specificity. Clarification: 'bystander edits' are unintended base changes near the target site that can compromise safety or efficacy.