Two-step model of leukocyte-endothelial cell interaction in inflammation: distinct roles for LECAM-1 and the leukocyte beta 2 integrins in vivo - von Andrian, U H; Chambers, J D; McEvoy, L M; Barqatze, R F; Arfors, K E; Butcher, E C (Proc Natl Acad Sci USA, 1991)