Several genes showing the highest level of expression in the four brain regions encode proteins involved in neuron structure and function, including the myelin basic protein (Mbp), the microtubule associated proteins 1B (Map1b) and 2 (Map2), and the stearoyl-Coenzyme A desaturase 2 (Scd2), and in the etiopathogenesis of Alzheimer's disease (Apoe) [42]. The gene discussed is SCD5; the disease is early-onset autosomal dominant Alzheimer disease.