Many diseases run in families due to the inheritance of particular sets of genes. If scientists can predict how genes function, we will be able to greatly improve the diagnosis and treatment of disease. Studying model species can make this possible. Cells follow a genetic blueprint composed of complex webs of interacting genes. These networks function to ultimately “turn on,” “turn off,” and “fine-tune” particular sets of genes for specific conditions, times, or locations. Our experiments are helping us understand how these gene networks function. Based on our understanding of regulatory networks, we are developing models that predict gene function.