Publisher Summary EBI-1 Ligand Chemokine (ELC) is a chemoattractant for T and B lymphocytes and myeloid progenitor cells. It is constitutively expressed in thymus and lymph nodes and may play a role in lymphocyte migration to these areas. This chapter describes the molecule ELC. The other names of this molecule are MIP-3β, CKB-11. The crossreactivity, sources, and bioassays are provided. The physiochemical properties of ELC are summarized in a table for human and mouse and the 3-D structure is not available. The gene structure for human ELC is on chromosome 9p13. The amino acid sequence for human ELC (Accession code: SwissProt Q99731) and mouse ELC (Accession code: SwissProt O70460) is presented. The structure of ELC receptor CCR7 is highlighted further. A list of further resources concludes the chapter.