Role of fractional exhaled nitric oxide in patients with sickle cell disease Agustín Muñoz-Cutillas; Sara Bellón-Alonso; Eduardo Bardón-Cancho; Santiago Rodríguez-Tubío-Dapena; Lucía Díez-Llamazares; Rosa Rodríguez-Fernández; Juan Luis Rodríguez-Cimadevilla;