All the genes in the human genome are now known, but it is not known in detail how they are regulated in normal development and misregulated in diseases. The fact that the number of genes a fruitfly has is quite similar to the number of genes of a human, has given rise to the idea that vast areas in the genome that do not contain genes have this regulatory function. In particular so called non-coding RNAs outside of genes have been implicated in genome regulation and disease. We study a particular non-coding RNA which when it is aberrantly made leads to the Beckwith-Wiedemann syndrome in which babies are born that are very large and can develop cancer. Our studies will help to understand better how the disease is caused, and will therefore help the families with children who have the disease.