Aside from the AD culprit genes related to Aβ production, the 68 AD-specific genes (not common with OXPHOS or HD or PD, hence also non-mitochondrial) in AD are dominated by genes related to signal transduction, including genes in the CAC (Calcium Voltage-Gated Channel), CAL (Calmodulin), CAP (Calpain, Calcium-Activated Neutral Proteinase), GRIN (Glutamate Ionotropic Receptor NMDA), ITPR (Inositol 1,4,5-Trisphosphate Receptor). This evidence concerns the gene ITPR1 and Parkinson disease.