CXCL1 and atherosclerosis: During early atherosclerosis, CXCL1/GRO-α immobilized on the surface of endothelial cells via heparin proteoglycans induces the firm adhesion of rolling monocytes expressing CXCR2 (Schwartz et al., 1994; Huo et al., 2001; Boisvert et al., 2006).