title: The present state of the second messenger theory.
mesh_terms: D000227:Adenine Nucleotides / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology; D004247:DNA; D006728:Hormones; D012313:RNA
chemical_list: D000227:Adenine Nucleotides; D006728:Hormones; D012313:RNA; D004247:DNA; D000242:Cyclic AMP