Patent ID: 7253007

Claim:
A method of identifying an agent that binds to CCX-CKR2 on a cell, the method comprising, contacting a plurality of agents and a CCX-CKR2 ligand to a polypeptide comprising an extracellular domain at least 95% identical to an extracellular domain of a CCX-CKR2 polypeptide comprising SEQ ID NO:2, or a fragment of the CCX-CKR2 polypeptide that binds SDF1 or I-TAC, wherein the CCX-CKR2 ligand is SDF1 or I-TAC; and selecting an agent that competes with I-TAC or SDF1 for binding to the CCX-CKR2 polypeptide or fragment thereof, thereby identifying an agent that binds to CCX-CKR2 on a cell.