- Urinary measurement of Na+/H+ exchanger isoform 3 (NHE3) protein as new marker of tubule injury in critically ill patients with ARF. du Cheyron, D., Daubin, C., Poggioli, J., Ramakers, M., Houillier, P., Charbonneau, P., Paillard, M. Am. J. Kidney Dis. (2003)