DARC (Duffy Antigen Receptor for Chemokines; also CD234) is a 40-46kD glycoprotein member of the Duffy family of silent heptahelical chemokine receptors. It is expressed in liver and on select neurons, erythrocytes and the endothelium of postcapillary venules. Unlike traditional chemokine receptors, DARC cannot signal through G-proteins as it lacks a DRYLAIVHA cytoplasmic motif. DARC has three potential functions: first, it binds circulating inflammatory-type chemokines, serving as a repository for future chemokine release; second, it acts as a vehicle by which chemokines are transported from the abluminal to the luminal side of endothelium; and third, it complexes with signal-transducing chemokine receptors to create a nonsignaling heterodimer. Mouse DARC is 334aa in length. It contains a 62aa N-terminal extracellular region, and a 28aa C-terminal cytoplasmic tail. There is one potential splice variant that shows a 42aa substitution for aa133-334. Collectively, over the four extracellular domains (aa1-62, 115-127, 186-205, 264-285), mouse DARC shares 52-75aa identity with human and rat DARC, respectively.