The article "Efficient In Vivo Genome Editing Using RNA-Guided Nucleases" by Woong Y. Hwang et al. demonstrates the effectiveness of CRISPR/Cas9 systems in vivo for targeted genetic modifications in zebrafish embryos. The authors show that RNA-guided nucleases, specifically Cas9, can induce site-specific DNA cleavage and mutations at multiple sites, including those previously resistant to TALENs. The system is highly efficient, with a success rate of over 80% at 11 tested sites, comparable to ZFNs and TALENs. The simplicity and scalability of the gRNA/Cas9 platform, compared to other genome editing technologies, are highlighted, along with its potential for multiplex genome editing. The study also discusses the design and optimization of gRNA expression vectors and the development of a web-based tool for identifying targetable sites. The results suggest that RNA-guided Cas9 nucleases offer a promising alternative for genome editing in a wide range of organisms.The article "Efficient In Vivo Genome Editing Using RNA-Guided Nucleases" by Woong Y. Hwang et al. demonstrates the effectiveness of CRISPR/Cas9 systems in vivo for targeted genetic modifications in zebrafish embryos. The authors show that RNA-guided nucleases, specifically Cas9, can induce site-specific DNA cleavage and mutations at multiple sites, including those previously resistant to TALENs. The system is highly efficient, with a success rate of over 80% at 11 tested sites, comparable to ZFNs and TALENs. The simplicity and scalability of the gRNA/Cas9 platform, compared to other genome editing technologies, are highlighted, along with its potential for multiplex genome editing. The study also discusses the design and optimization of gRNA expression vectors and the development of a web-based tool for identifying targetable sites. The results suggest that RNA-guided Cas9 nucleases offer a promising alternative for genome editing in a wide range of organisms.