EPHA4 and mild neurocognitive disorder: To further investigate whether EphA4 signalling functions at the level of motor neurons to cause death in MND, SOD1G93A mice with specific EphA4 gene deletion in choline acetyltransferase (ChAT)-expressing cells were obtained by crossing them with EphA4flox/flox and ChAT-CreKI/KI mice on a SOD1G93A genetic background [22].