The impact of CRISPR-Cas9 on target identification and validation.

The addition of an RNA-guided nuclease, Cas9, to the gene editing toolbox has increased the accessibility of gene editing technologies by greatly simplifying the design of editing reagents. Only a single 75-100 nucleotide RNA is required to guide Cas9 to the target gene of interest, which has meant that the established infrastructure of short-hairpin RNA interference screen could be readily adapted to genome-wide knock out screens. Cas9-based editing technology should streamline the generation of animal and cell-line models, make the generation of activity-dead mutations in target validation routine, and enable the discovery of a new generation of targets across therapeutic areas.