CX3CL1, ABCD-3, C3Xkine, CXC3, CXC3C, fractalkine, neurotactin, NTN, NTT, SCYD1, C-X3-C motif chemokine 1, CX3C membrane-anchored chemokine, Neurotactin, Small-inducible cytokine D1

CX3CL1, also known as fractalkine isoform 1, is a member of the CX3C chemokine family. It acts as a ligand for both CX3CR1 and integrins. This protein acts different ways dependent on its form. The soluble form is chemotactic for T-cells and monocytes and not for neutrophils. The membrane-bound form promotes adhesion of those leukocytes to endothelial cells. This protein plays a role in regulating leukocyte adhesion and migration processes at the endothelium. It is also up-regulated in the hippocampus during a brief temporal window following spatial learning, the purpose of which may be to regulate glutamate-mediated neurotransmission tone. This indicates a possible role for the chemokine in the protective plasticity process of synaptic scaling.