According to a genetic study, the differential expression of SCN2A, GRIA1, and KCNJ9—genes that encode the α2 subunit of the neuronal sodium channel, the AMPA-type subunit 1 receptor, and the G protein-activated inward rectifier potassium channel 3, respectively—is consistent in both AD and epilepsy. The gene discussed is KCNJ9; the disease is Alzheimer disease.