This morning it was announced that two American scientists won the Nobel Prize in Physiology and or Medicine, for their 1998 discovery of a hidden network of genes. It may seem odd that a network of genes could lurk undiscovered for so long. But the cell is very much a mysterious place. In the 1950s, scientists established the basic model for how genes work. A gene is made of DNA, the cell makes a single-stranded copy of a gene in a molecule called RNA, and it then uses the RNA as a template for building a protein. This so-called Central Dogma proved to be correct for many thousands of genes, but not all of them. In many cases, a