Lymphotactin is the only known member of the C-chemokine family and signals through the receptor XCR1, formally known as GPR5. The spleen shows the highest level of lymphotactin compared to peripheral leukocytes, lung, colon and small intestine. Lymphotactin is chemotactic towards lymphocytes but not towards monocytes or neutrophils. Recombinant human Lymphotactin is a 10.0 kDa protein consisting of 92 amino acid residues.