Diagram of the CRISPR prokaryotic antiviral defense mechanism1 (echo:: @ ⌗) Footnotes Horvath P, Barrangou R (January 2010). “CRISPR/Cas, the immune system of bacteria and archaea”. Science. 327 (5962): 167–170. Bibcode:2010Sci…327..167H. doi:10.1126/science.1179555. PMID 20056882. ↩