This book gives an overview of various interactomes involved in dorsal ventral (DV) and anterior posterior (AP) guidance, their mechanisms of action, subcellular localizations, and functional roles. It will provide readers a better understanding of the development of the nervous system, which in turn will help to find cures to various neural and other disorders. In nematodes there are two types of guidance systems, including DV and AP guidance. The signaling process that guides the growth cones along the DV axis has remained intact in both vertebrates and invertebrates. The adaptor protein UNC-53 appears to play a part in migration along the AP axis in both worms and their human homologs. "Neuron Navigators" (NAV) are also involved in nervous system development .