Rantes, also known as CCL5, is the protein classified as a chemotactic cytokine or chemokine. This protein is a chemotactic for blood monocytes, memory T helper cells, eosinophils and basophils, and plays an active role in recruiting leukocytes into inflammatory sites. Rantes also induces the proliferation and activation of certain natural-killer (NK) cells to form CHAK (CC-Chemokine-activated killer) cells.