PARC is a CC chemokine that shows the highest sequence similarity to the CC chemokine MlP-la. It is expressed in lung and lymphoid tissues, and induced in monocytes by TH2-associated cytokines. In contrast to MIP-lo and most other CC chemo-kines, PARC is not chemotactic for monocytes and granulocytes. Since PARC attracts only a subset of T lymphocytes and is expressed in dendritic cells of lymphoid tissues, one of the functions of PARC may be the generation of primary immune responses. The human gene for PARC (SCYA18) resides in the major CC chemokine cluster at chromosome 17q 11.2, while other lymphocyte-specific CC chemokine genes are located on chromosomes other than chromosome 17. The mouse ortholog of PARC might not exist in the mouse genome.