CXCR7 in tumorigenesis and progression.

Chemokines, a family of small cytokines, were initially characterized as proinflammatory chemoattractant cytokines that regulated cell trafficking and adhesion. Today, attention focuses on chemokines because evidence shows that they play a critical role in tumor initiation, promotion, and progression. CXCR7, a seven-transmembrane G-protein-coupled CXC chemokine receptor, has recently been identified as binding with high affinity to chemokines CXCL11 (I-TAC) and CXCL12 (SDF-1).