OBJECTIVE: Restless legs syndrome (RLS) is a sensorimotor disorder marked by an uncontrollable urge to move the legs. A pathophysiological hallmark of RLS is brain iron deficiency. The endothelial cells (ECs) of the blood-brain barrier (BBB) are responsible for regulating brain iron uptake. Our objective is to determine if brain iron uptake is altered in ECs in RLS. METHODS: Human ECs were generated from induced pluripotent stem cells (iPSCs). ECs were exposed to RLS (nā=ā14) or control cerebros...