Based on the fact that RLS/WED is a disease usually presenting clinical signs in the evening and that women have higher risk than men1, we explored the profile of motor function in Map2k5+/– mutant mice by performing a series of behavioral tests including open field test, rotarod test, and 12 h–12 h cycle infrared locomotor activity pattern. The gene discussed is MAP2K5; the disease is restless legs syndrome.