We need to pause right here and point out two things about the Central Dogma. First of all, it is, in fact, central to an understanding of the molecular biology, and I would consider it a personal favor if you would carry the preceding figure in your head until you croak. Second, it is dogma, and like all dogma it carries a faint whiff of poo-poo. For example, the HIV virus, always a troublemaker, has an RNA genome which it transcribes into DNA for insertion into the host genome. In this situation information flows from RNA to DNA. What’s more, as you may recall many proteins regulate transcription and translation, which one might argue represents a flow of information from protein back to RNA and DNA. But these are quibbles. For all practical intents and purposes, the Central Dogma rules: information flows from DNA to RNA to protein. But how?