Illustration of the mini CRISPR IscB (insertion sequences Cas9-like B) protein (blue) complexed to guide wRNA (yellow, structured ribonucleic acid) and target DNA (deoxyribonucleic acid, green and red). CRISPR is used in genome editing to cut DNA at a specific site. The CRISPR-Cas complexes that were first discovered are too large for some common genome editing vectors such as the adenovirus-associated virus (AAV). IscB, which is used by transposons, sequences of DNA that can move, or transpose, themselves to new positions within the genome of a single cell, are small enough to fit such vectors.