UNC5B and neuroblastoma: Netrin‐1, the ligand for UNC5B, is an axon guidance molecule that plays also a crucial role during neuroblastoma development as well as in colorectal and breast tumorigenesis, by regulating apoptosis (Delloye‐Bourgeois et al., 2009; Fitamant et al., 2008; Mazelin et al., 2004).