The cerebellum is a complex region of our brain involved in the coordination of our movements and cognition. Evidence shows that cerebellum is involved in several brain disorders such as ataxia (inability to move properly), autism, and medulloblastoma (the most prevalent brain tumor in children). The cerebellum is made of different cell types. Among them, the most numerous cell type, the granule cells, contribute to many crucial cerebellar functions. Indeed, an uncontrolled division of granule cells results in the most common form of pediatric brain tumor, the medulloblastoma.