They subsequently bind and activate chemokine receptors, G protein-coupled receptors (GPCRs) imbedded in the cell membranes of leukocytes, thereby inducing leukocyte adhesion to the vessel wall, morphological changes, extravasation into the inflamed tissue, and chemotaxis along the chemokine gradient to the site of injury or infection [1]. The gene discussed is ACKR3; the disease is infection.