Crick’s central dogma of information flow: DNA→RNA→protein. The information to replicate DNA is inherent in its structure (curved arrow). Information flows from DNA to RNA by transcription. Information flows from RNA to protein by translation. In some instances, information can also flow backward, from RNA to DNA (reverse transcription), and some viruses encode enzymes that produce RNA from RNA (not shown in the figure). Other types of information flow exist that do not fall within Crick’s central dogma.