- The chemokine receptor CCR4 in vascular recognition by cutaneous but not intestinal memory T cells. Campbell, J.J., Haraldsen, G., Pan, J., Rottman, J., Qin, S., Ponath, P., Andrew, D.P., Warnke, R., Ruffing, N., Kassam, N., Wu, L., Butcher, E.C. Nature (1999)