How specific is CRISPR/Cas9 really?

- Concerns about CRISPR specificity led to new methods for detection and avoidance.
- Some studies reported many off-target events, while others observed few.
- High or low specificity is a property of the guide RNA used, not CRISPR/Cas9 per se.
- The current challenge is to find the most specific guide RNA.
- The specificity determinants for Cas9 nuclease and dCas9 binding are different.