Several agonists induce the rapid increase in cytosolic free calcium (Ca2+) concentration upon cell activation. E.g. the chemokines CXCL8 and CXCL7 cause Ca2+ release from intracellular pools and influx through the chemokine receptor CXCR2. In our work, we have identified the chemokine receptor CXCR2 as a functional receptor for the chemokine-like cytokine MIF, which acts as a non-cognate ligand of CXCR2 (ref. 1). As MIF binding to CXCR2 resulted in typical chemokine effects such as cell arrest and chemotaxis, we also investigated the Ca2+ mobilization as an early signal of MIF-induced cell activation.