Interleukin-20 is a protein belonging to the IL-10 family of cytokine

Cytokine

Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...

s. IL-20 is produced by activated keratinocyte

Keratinocyte

Keratinocytes are the predominant cell type in the epidermis, the outermost layer of the human skin, constituting 95% of the cells found there. Those keratinocytes found in the basal layer of the skin are sometimes referred to as "basal cells" or "basal keratinocytes"...

s and monocyte

Monocyte

Monocytes are a type of white blood cell and are part of the innate immune system of vertebrates including all mammals , birds, reptiles, and fish. Monocytes play multiple roles in immune function...

s and transmits an intracellular signal through two distinct cell-surface receptor complexes on keratinocytes and other epithelial cells. IL-20 regulates proliferation

Cell growth

The term cell growth is used in the contexts of cell development and cell division . When used in the context of cell division, it refers to growth of cell populations, where one cell grows and divides to produce two "daughter cells"...

 and differentiation of keratinocytes during inflammation, particularly inflammation associated with the skin. In addition, IL-20 also causes cell expansion of multipotential hematopoietic progenitor cells.