Dysregulation of key trophic factor receptors in the cell cycle is involved in the pathogenesis of AD, possibly mediated via glutamatergic synapse (GRIN2A), long-term potential (GRIN2A, GRIA2), MAPK (TNFRSF1A), and PI3K-Akt (CHRM1, RXRA) signaling pathways. The gene discussed is RXRA; the disease is Alzheimer disease.