Human genome sequencing revealed the order of the 3 billion letters of A, C, G and T, but not what they mean, much less the grammar that gives them meaning. A study by the Karolinska Institute in Stockholm in the latest edition of international science journal Nature (527; 384-388,2015) shows that the “grammar” of the human genome is more complex than the most complicated languages spoken in the world. “The genome contains all the information needed to build and maintain an organism, but it also holds the details of an individual’s risk of developing common diseases”, says lead author, Arttu Jolma. The cells have almost identical genomes, but differ from each other according to the active (expressed) genes that give them their function. Each gene has a regulatory region containing the instructions that control when and where the gene is expressed (JR Zárate. DM 16/22-XI-2015).