CCR2 antagonist 4 (Teijin compound 1) is a potent and specific CCR2 antagonist, with IC₅₀s of 180 nM for CCR2b. CCR2 antagonist 4 potently inhibits MCP-1-induced chemotaxis with an IC₅₀ of 24 nM^[1]. In Vitro: Ile263 and Thr292 in CCR2 contribute significantly to binding of Teijin compound 1 in CCR2. Residue Glu291 in TM7, a highly conserved residue in many CC chemokine receptors, contributes substantially to binding of the protonated CCR2 antagonist 4, and CCL2. His121 on TM3 and Ile263 on TM6 also strongly interact with CCR2 antagonist 4^[2]. In Vivo: In ApoE-deficient mice, Vp-TSL targets specifically aortic plaque endothelial VCAM-1 and CCR2 antagonist 4 reduces the mouse monocyte/macrophage cell line (RAW 264.7) adhesion/ infiltration into the aorta^[3].