Confirming the central role that is played by STAT3 in psoriasis pathogenesis, the groups of Di Giovanni and Sano have demonstrated that Keratin5.Stat3C transgenic mice, overexpressing constitutively active STAT3 in keratinocytes, develop a skin phenotype closely resembling psoriasis in response to wounding or to TPA treatment. The gene discussed is STAT3; the disease is psoriasis.