Mouse Darc (Ackr1) is an atypical chemokine receptor expressed predominantly on erythrocytes and endothelial cells, where it binds diverse inflammatory chemokines without classical GPCR signaling. By functioning as a chemokine reservoir and transporter, Ackr1 regulates chemokine gradients and leukocyte trafficking during inflammation. Studies in Ackr1-deficient mice highlight its role in immune homeostasis and neutrophil recruitment, establishing Darc as an important regulator of systemic chemokine availability and inflammatory responses.