For instance, NGF/TrkA induces differentiation, apoptosis, and growth inhibition in neuroblastoma and medulloblastoma (Chou et al., 2000; Lavenius et al., 1995; Matsushima and Bogenmann, 1993), and high expression of TrkA is considered a favorable prognostic indicator in neuroblastoma (Nakagawara et al., 1993). This evidence concerns the gene NTRK1 and medulloblastoma.