May play an important role in inflammation and regeneration of skeletal muscle (PubMed:11415443). Essential for embryonic development (By similarity). Has chemotactic response in monocytes, neutrophils and lymphocytes (PubMed:11415443). Binds CCR4 (PubMed:16137713). Partly inhibited by interleukin 10. Isoform 1, isoform 2, isoform 3 and isoform 4 have highest expression levels in adult spleen, lung, testis, ovary, peripheral blood leukocyte, placenta, pancreas, and in fetal brain, skeletal muscle, thymus and heart. Lower expression levels in adult skeletal muscle, liver, thymus colon, prostate and fetal spleen and liver. Belongs to the chemokine-like factor family.