IL20 is a cytokine structurally related to interleukin 10 (IL10). IL20 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.