RANTES (regulated on activation, novel T expressed, and secreted) is a chemoattractant cytokine (chemokine) first identified less than a decade ago. It functions in the process of attracting immune cells, including monocytes, T lymphocytes and eosinophils, into sites of inflammation. It is also involved in the activation of some cell types and prolongation of the immune response in space and time. For these reasons, it appears that RANTES may play an important role in cell-mediated and chronic forms of transplant rejection.