[4] Under normal circumstances it is highly expressed in human lungs, prostate, kidneys, hair follicles and salivary and mammary glands.

[6][7][8] In the extracellular environment, it can be found as a homodimer in vivo and in vitro, but it also exists in monomeric, polymeric and multimeric forms.

[8][11] It also plays a role in differentiation, regeneration of tissues and healing[12][13] and it was shown it attract eosinophils by chemotaxis.

[15] Chromosomal rearrangements and altered expression of this gene have also been implicated in breast cancer.

[19] Although in most cancers it has been found in reduced levels, there are studies that show that in some cases it is overproduced.