In our study, we have discovered chemokine-like functions for the cytokine MIF such as induction of leukocyte arrest on endothelial cells. Cell adhesion requires the activation, i.e. by arrest chemokines, of integrins on the cell surface, which subsequently interact with adhesion molecules, such as VCAM-1 and ICAM-1. The latter interacts with the alpha-L beta-2 integrin. As MIF, like CXCL8, induced monocyte arrest on ICAM-1-expressing CHO cells1, we investigated the direct effect of MIF on integrin activation.