. "The directed movement of sodium ions (Na+) into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore." . . . "sodium ion transport" . "mitochondrial sodium/calcium ion exchange" . "sodium:calcium exchange" . "sodium/potassium transport" . "sodium channel auxiliary protein activity" . "sodium transport" . "sodium:solute transport" . . . . . . .