Adapted from a naturally occurring bacterial immune system, CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeats. One of the proteins in the CRISPR system is known as CRISPR-associated 9 protein or Cas9 protein, which acts as a pair of ‘molecular scissors’ to cleave DNA. Researchers have co-opted the bacterial CRISPR/Cas9 system to make specific changes in the DNA of humans, other animals and plants.

CRISPR/Cas9 was first harnessed in 2012 as a genome editing tool in the lab. More recently, scientists have begun engineering and testing CRISPR systems to be very specific to a desired genetic target.