Netrins control guidance of CNS commissural axons and peripheral motor axons. Its association with either DCC or some UNC5 receptors will lead to axon attraction or repulsion, respectively. Binding to UNC5C might cause dissociation of UNC5C from polymerized TUBB3 in microtubules and thereby lead to increased microtubule dynamics and axon repulsion (By similarity). Involved in dorsal root ganglion axon projection towards the spinal cord (By similarity). It also serves as a survival factor via its association with its receptors which prevent the initiation of apoptosis. Involved in colorectal tumorigenesis by regulating apoptosis (By similarity). Binds to its receptors; DCC, UNC5A, UNC5B, UNC5C and probably UNC5D. Binds to its receptor; DSCAM (By similarity). Interacts with APP (By similarity). Mainly secreted.