CXCR4 Antagonist USL311

**Semantic type:** Pharmacologic Substance

**Definition:** An orally bioavailable inhibitor of C-X-C chemokine receptor type 4 (CXCR4), with potential antineoplastic activity. Upon administration, USL311 binds to CXCR4, thereby preventing the binding of stromal-cell derived factor-1 (SDF-1 or CXCL12) to CXCR4 and inhibiting CXCR4 activation, which may result in decreased proliferation and migration of CXCR4-expressing tumor cells. CXCR4, a chemokine receptor belonging to the G protein-coupled receptor (GPCR) family, plays an important role in chemotaxis and angiogenesis, and is upregulated in several tumor cell types.

**Synonyms:** - CXCR4 Inhibitor USL311 - USL 311 - USL-311 - USL311