Given that deletion of trans-synaptic partners (e.g., NGL-2 and its presynaptic ligand netrin-G2) in mice often results in phenotypic similarities [83–86], the abnormalities at the synapse, systems, and behavioral levels observed in Ngl3−/− mice may help us understand how LAR-RPTPs are associated with specific psychiatric disorders. The gene discussed is LRRC4; the disease is psychiatric disorder.