CX3CL1 (chemokine (C-X3-C motif) ligand 1) or fractalkine is a membrane protein, which is the only member of CXC3 family. Its chemokine domain (CKD) anchors it to the cell membrane through its mucin-like stalk. It acts as a ligand for the G-protein coupled receptor CX3CR1, which is found on smooth muscle cells, T-cells, natural killer (NK) cells and monocytes. Fractalkine is expressed on epithelial, endothelial and smooth muscle cells and neurons.

CX3CL1 (chemokine (C-X3-C motif) ligand 1) or fractalkine, along with CX3CR1 is involved in various disorders such as atherosclerosis, multiple sclerosis, neuropathic pain and rheumatic disorders. It facilitates the proliferation and survival of primary human vascular smooth muscle cells in an epidermal growth factor receptor (EGR)–dependent manner. It plays an essential role in cell survival and promotes the survival of cells such as monocytes, T-cells and microglia. In humans, it is thought to be involved in atherogenesis, and thus, might have potential as a target in treatment of cardiovascular disease. In patients with sickle cell disease (SCD), the serum levels of this chemokine is increased, thus implicating it in the pathogenesis of inflammation associated with SCD.

Leukocyte chemoattractant protein and member of the chemokine superfamily possessing a CX₃C motif.

Recombinant extracellular fractalkine simulates the shed form of the chemokine and chemoattracts neutrophils and T cells.

Simulates the shed form of the chemokine and chemoattracts neutrophils and T cells.

Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 1.25 mg of bovine serum albumin.

The biological activity is measured by its ability to chemoattract freshly isolated peripheral blood lymphocytes.

Extracellular domain (amino acids 1-337) fused to a 6X histidine tag at the C-terminus.