CD198, also known as C-C chemokine receptor type 8 （CCR8）, is a 41 kD G-protein coupled receptor with seven transmembrane regions. It belongs to the C-C chemokine receptor family and is expressed in various cell types, including a subset of thymocytes, Tregs, NKT cells, Th2-polarized cells, macrophages, monocytes, and monocyte-derived dendritic cells. CCR8 plays a crucial role in mediating chemotaxis and is involved in the apoptosis of thymocytes. It is also associated with allergic inflammation and has potential as a therapeutic target for conditions like HIV-1 infection. The receptor binds to ligands such as CCL1 and CCL16 and has high affinity for viral chemokines like vMIP-I, vMIP-II, and vMCC-I.