E-selectin and its ligands are essential for extravasation of leukocytes in inflammation. Here, we report that basigin (Bsg)/CD147 is a ligand for E-selectin that promotes renal inflammation in ischemia/ reperfusion. The selectins and their ligands are essential for leukocyte tethering/rolling on endothelial cells and the initiation of inflammatory response. The selectins are C-type lectins and consist of three members, i.e., P-, L-, and E-selectin. 1,2 P-selectin is expressed upon inflammatory stimulation in platelets and endothelial cells. L-selectin is constitutively expressed on the tip of leukocyte microvilli and implicated in lymphocyte homing to lymph nodes. 3 E-selectin is specifically induced in the endothelium upon inflammatory stimulation. Thus, E-and P-selectin closely collaborate with one another and play a major role in leukocyte recruitment to inflammatory sites. 4 -6 Among the several glycoproteins reported to bind to E-selectin, three have been identified as representative physiologic E-selectin ligands on neutrophils. There are P-selectin glycoprotein ligand-1 (PSGL-1), E-selectin ligand-1, and CD44, and all three play distinct roles during tethering and slow rolling of neutrophils on the endothelium. 7 A minimal recognition motif for all selectins is sialylated and fucosylated glycan determinants, such as sialyl Lewis X, that decorate the terminal extensions of carbohydrates of these molecules. 8,9 However, because of the poor immunogenicity of highly gly-