Proven and novel strategies for efficient editing of the human genome

• Zinc-finger nuclease mediated gene editing has reached the clinic.
• TALE nucleases are highly specific.
• The CRISPR/Cas9 platform allows for orthogonal multiplex genome editing.
• Genome engineering can be combined with editing of the epigenome or transcriptome.

Targeted gene editing with designer nucleases has become increasingly popular. The most commonly used designer nuclease platforms are engineered meganucleases, zinc-finger nucleases, transcription activator-like effector nucleases and the clustered regularly interspaced short palindromic repeat/Cas9 system. These powerful tools have greatly facilitated the generation of plant and animal models for basic research, and harbor an enormous potential for applications in biotechnology and gene therapy. This review recapitulates proven concepts of targeted genome engineering in primary human cells and elaborates on novel concepts that became possible with the dawn of RNA-guided nucleases and RNA-guided transcription factors.