Historically, the following text describes a biotechnology tool.

CRISPR-Cas9 is a genome editing technology that allows researchers to permanently modify genes in living cells and organisms to correct mutations at precise locations in the human genome to treat genetic causes of disease. It functions like a pair of molecular scissors, capable of cutting DNA strands at specific sequences. Once the DNA is cut, the cell's natural repair mechanisms kick in, allowing scientists to add or remove genetic material.