Koo and colleagues demonstrate that Un1Cas12f1 recognizes an expanded PAMs, and enables multiplexed genome editing from a single CRISPR array. Delivered as an all-in-one AAV, this compact Un1Cas12f1 system excises Dmd exon 23 in vivo, restores the reading frame and dystrophin expression in a mouse model of Duchenne muscular dystrophy.