<unk>  is a cytokine, being a smaller protein involved in cell signaling. The active form of the protein is found extracellularly as a disulfide-linked homodimer, and is thought to be produced by proteolytic cleavage of membrane-bound precursors. Four transcript variants encoding three different isoforms (a proteoglycan, glycoprotein and cell surface protein) have been found for this gene.
Macrophage colony-stimulating factor
Macrophage-activating factor
Leukemia inhibitory factor
Hemopoietic growth factor
Thymic stromal lymphopoietin
Interleukin
Major basic protein
Tumor necrosis factor