Human Fractalkine (CX3CL1) is a member of the CX3C family of chemokines. Human Fractalkine contains both chemokine and mucin domain. The soluble form of Fractalkine is chemotactic for T-cells and monocytes, but not for neutrophils. The membrane bound form of Fractalkine promotes leukocytes adhesion to endothelial cells. Fractalkine regulates leukocyte adhesion and migration processes at the endothelium and binds to CX3CR1. Natural Human Fractalkine is produced as a long protein (373-amino acid). The mucin-like stalk permits it to bind to the cell surface.