“…Furthermore, current evidence suggests that there is little predictability in pegRNA design and efficacy, and although efforts have been made to further elucidate design criteria of pegRNAs, only little improvement has been made in this regard since the initial description of prime editors by Anzalone and colleagues (Anzalone et al, 2019;Kim H. K. et al, 2021). Thus, identifying novel effective pegRNAs is currently accomplished by labor-intensive manual screening, which has been somewhat aided by pegRNA design tools developed by us and others (Anderson et al, 2021;Chow et al, 2021;Hsu et al, 2021;Hwang et al, 2021;Siegner et al, 2021;Standage-Beier et al, 2021;Mathis et al, 2023). Alternatively, candidate pegRNAs can be identified using large-scale screening approaches, allowing simultaneous testing of a high number of pegRNAs for new targets (Kim H. K. et al, 2021;Jang et al, 2021;Yarnall et al, 2022).…”