GRM5 and acrodermatitis enteropathica: This may be due to that the autoantibodies produced in patients with AE target proteins localized in neuronal synapse (synaptic membrane or space), such as NMDAR, LGI, AMPAR, GABA receptors, mGluR5, D2R, and Neurexin-3α, causing these proteins crosslinking and internalization and affecting synaptic signal transmission [34], which may induce the host response to repair the synapse organization and recover the synaptic signaling.