Dear Editor,

Recently, zinc finger nuclease, transcription activator-like effector nuclease, and RNA-guided Cas9 endonuclease (Cas9) have emerged as powerful means for genome editing (Conklin, 2013; Gaj et al., 2013). These nucleases are efficient in generating double-strand breaks in the genome that can be repaired by error-prone nonhomologous end joining leading to a functional knockout (KO) of the targeted gene or used to integrate a DNA sequence at a specific locus through homologous recombination. Although the Cas9 system has been shown highly efficient in generating genetically engineered mice and rats (Li et al., 2013a, b; Wang et al., 2013), its feasibility in the rabbits still needs be determined. Here we report the use of Cas9 system to effectively generate targeted mutations in rabbit embryos and the production of KO rabbits.