CCRL1/ACKR4 is an atypical chemokine receptor that functions primarily as a chemokine scavenger, binding CCL19, CCL21, CCL25, and CXCL13 to shape local chemokine gradients rather than inducing classical GPCR-mediated chemotaxis. Expressed in lymphatic endothelium, epithelial barriers, and stromal compartments, ACKR4 plays a key role in dendritic cell trafficking, lymphocyte positioning, and tissue immune homeostasis. Dysregulation of ACKR4 can alter barrier immunity, inflammatory responses, and tumor immune organization, highlighting its importance as a non-signaling regulator of chemokine networks.