Riley, 11, has a slow-growing and rare benign brain tumor called a pylocytic astrocytoma. She calls her tumor Roger, and says, “I kicked his butt.” The tumor, located between her optic nerve and pituitary gland, can’t be taken out surgically. It will require lifelong monitoring, and drug therapy and radiation therapy when she is older— to keep it from growing into her optic nerve and affecting her vision. This is the kind of tumor that Sonia Franco’s minibrain model could impact, providing new information about how they grow and the therapies that may work best.