The central dogma of molecular biology, formulated by Francis Crick and popularized by James Watson, emphasizes the uni- directional transfer of genetic information from DNA to RNA to proteins. This principle has greatly influenced our scientific research and perspective of life. However, it fails to adequately account for the following discoveries: 1) there are different kinds and different levels of biological information; 2) the meaning and usage of biological information are system-dependent; 3) no information flow is possible without the cooperative function of DNA, RNA and proteins; 4) the coding system and the decoding system have to match; and 5) proteins, with the help of RNAs, control whether and how DNA is replicated as well as the stability, accessibility and usability of DNA. Thus, we propose updating the central dogma to the following: The central principle of molecular biology is regulated, dynamic, system-dependent information coding and decoding.