Genome engineering models are essential tools, which are widely used in life science research, including gene function research, cancer research and drug discovery. In particular, in order to faithfully create human disease models, it is advantageous to develop a gene-editing technology that enables predefined and precise sequence modifications in the genome of a model organism. The Clustered, Regularly Interspaced, Short Palindromic Repeat (CRISPR)-associated 9 (Cas9) system has proven to be a simple, efficient and reliable approach for genome editing in zebrafish. CRISPR-Cas9 gene editing has proven to be highly specific, more efficient and easier to customize compared with other methods.