GRIN1 and Alzheimer disease: Of note, the NMDA receptor GluN1 subunit was increased 6-fold in postmortem AD frontal cortex compared with controls,83 supporting a key role for elevated NMDA receptor activity in glutamate-mediated neurodegeneration.78 Moreover, Aβ was shown to induce degradation of GKAP, the protein encoded by DLGAP1.84 Further studies are needed for clarifying how the latter observation is related to the reduced DLGAP1 expression observed in our AD LCLs (Figure 3b).