May act as a soluble regulator of keratinocyte differentiation.
Subcellular locations: Secreted
Expressed in epidermis; in the spinous and granular layers and in placenta. Also found in the epithelia of the small intestine, macrophages of the lung and endothelial cells of the lung. Isoform 15 is expressed in epidermis and placenta. Isoform 1 is expressed in epidermis.