NPTN and schizophrenia: Embigin, basigin and neuroplastin are in the same small subgroup of the immunoglobulin superfamily (IgSF) [6], while neuroplastin protein is coded by NPTN which was proven to be a susceptibility gene for schizophrenia [7] and played an important role in long-term potentiation, synaptic plasticity and neurite outgrowth, probably related to learning, memory and emotion [8].