 Retrons are DNA sequences that encode for reverse transcript disease and a unique single-stranded DNA slash RNA hybrid called multi-copy single-stranded DNA, MS DNA. In 2020, it was discovered that these elements could activate an abortive infection pathway in response to bacteriophage, phage infection. This activation prevents the virus from replicating and kills the host cell, thus preventing the virus from spreading. Under certain conditions, retrons can provide a selective advantage to bacterial populations, allowing them to survive predation by phages. This article was authored by Brandon A. Berryhill, Joshua A. Manuel, Rodrigo Garcia, and others.