Transcriptional levels of genes associated with synaptic plasticity, learning, and memory processing, including immediate early genes such as c-Fos, JunB, activity-regulated cytoskeleton-associated protein (Arc), and early growth response gene-1 (Egr-1), are decreased in the hippocampus in AD patients and animal models [20, 23]. The gene discussed is ARC; the disease is Alzheimer disease.