SHISA4 (Shisa Family Member 4) is a protein involved in regulating synaptic function and neuronal excitability. It modulates the activity of important receptors in the central nervous system, including AMPA and NMDA receptors, playing a key role in neuronal signaling and synaptic plasticity. Because of its role in synaptic modulation, SHISA4 is of interest in research on neurological disorders and synaptic dysfunction.