Interleukin 20 is a protein that in humans is encoded by the IL20 gene. Interkeukin 20, or IL-20, also includes other cytokines, including IL-19, IL-20, IL-22, IL-24, and IL-26. Based on common structural and functional properties of IL-20's receptors and target cells, these cytokines constitute the same subfamily, IL-20.
The protein encoded by this gene is a cytokine structurally related to interleukin 10 (IL-10). This cytokine has been shown to transduce its signal through signal transducer and activator of transcription 3 (STAT3) in keratinocytes. A specific receptor for this cytokine is found to be expressed in skin and upregulated dramatically in psoriatic skin, suggesting a role for this protein in epidermal function and psoriasis.
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