With regard to Huntington's Disease, normal huntingtin is associated with NMDARs via PSD-95 but mutant huntingtin impairs the interaction between PSD-95 and huntingtin, leading to excitotoxicity through increased NMDA receptor activity [21], which is a key feature of this neurodegenerative disease [22–24]. The gene discussed is DLG4; the disease is neurodegenerative disease.