Chemokine_CXC: 1 of 4 subgroup designations based on the arrangement of the two N-terminal cysteine residues; includes a number of secreted growth factors and interferons involved in mitogenic, chemotactic, and inflammatory activity; many members contain an RCxC motif which may be a general requirement for binding to CXC chemokine receptors; those with the ELR motif are chemotatic for neutrophils and have been shown to be angiogenic, while those without the motif act on T and B cells, and are typically angiostatic; exist as monomers and dimers, but are believed to be functional as monomers; found only in vertebrates and a few viruses. See CDs: Chemokine (cd00169) for the general alignment of chemokines, or Chemokine_CC (cd00272), Chemokine_C (cd00271), and Chemokine_CX3C (cd00274) for the additional chemokine subgroups.