movement of tethered, spherical leukocytes along the endothelial surface of the microvasculature. The tethering and rolling involves interaction with selectins and other adhesion molecules in both the endothelium and leukocyte. The rolling leukocyte then becomes activated by chemokines, flattens out, and firmly adheres to the endothelial surface in preparation for transmigration through the interendothelial cell junction. (From Abbas, Cellular and Molecular Immunology, 3rd ed)