Some use cas9, such as dead cas9 (has endonuclease activity removed), and others do not. Great interview where Dr. George Church talks base editing and CRISPR:

Some use cas9, such as dead cas9 (has endonuclease activity removed), and others do not. Great interview where Dr. George Church talks base editing and CRISPR: https://www.foundmyfitness.com/episodes/george-church https://www.foundmyfitness.com/episodes/george-church