Disks large-associated protein 4 (DLGAP4, SAPAP4) belongs to the SAPAP family. The function of DLGAP4 is not clear. It has been linked to early-onset cerebellar ataxia [].SAPAP family members are PSD-95/SAP90-associated proteins localised at postsynaptic density []. Postsynaptic density (PSD) is a specialised submembranous structure within which synaptic membrane proteins are linked to cytoskeleton and signalling proteins. PSD-95/SAP90 is one of the major components of PSD, and functions as a scaffold protein for various ion channels and associated signalling molecules.