STAT3 and psoriasis: Transgenic mice overexpressing a constitutively active form of STAT3 in basal keratinocytes (K5.Stat3C) develop a mild, psoriasis‐like phenotype that aggravates in response to wounding or 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) treatment (Sano et al, 2005).