The role of CRISPR–Cas systems in defence against mobile genetic elements is well established, but there is increasing evidence that these systems have alternative functions beyond adaptive immunity. In this Review, Staals, van der Oost and colleagues explore these non-canonical functions of CRISPR–Cas systems with relevant consequences for CRISPR-based genome editing applications.
- Prarthana Mohanraju
- Chinmoy Saha
- John van der Oost
