Thanks to advances in genomics in recent decades, researchers now know the genetic mutations responsible for many diseases. However, researchers often still do not know how the mutation leads to the disease—what it changes inside of cells to cause symptoms. Figuring out this missing piece, the disease mechanism, not only advances understanding of the disease but can be essential for developing a treatment or prevention. For example, if researchers know that a mutation leads to the creation of a faulty protein, and that the build-up of this faulty protein causes the disease, then they can design drugs that will lead to the protein's destruction.