When the human genome was sequenced, biologists were surprised to find that very little of the genome—less than 3 percent—corresponds to protein-coding genes. What, they wondered, was all the rest of that DNA doing? It turns out that much of it codes for genetic snippets known as long non-coding RNAs, or lncRNAs. In recent years, scientists have found that these molecules often help to regulate which genes get turned on or off inside a cell. However, little is known about the specific roles of the thousands of lncRNAs discovered so far.
