Physiology - Chemokines beyond inflammation

The chemokine receptor CXCR4 has been implicated in processes from growth regulation and inflammation to entry of the human immunodeficiency virus. Two groups have now found that mice lacking CXCR4 have a similar phenotype to those that lack its ligand SDF-1 — namely, serious developmental defects in the immune and circulatory systems. But, surprisingly, the mice also show defects in the central nervous system and in the formation of blood vessels within the gastrointestinal tract, indicating that chemokines have much more widespread functions than was initially thought.