Furthermore, using mice in which the expression of a constitutively active/dimerized form of Stat3 (Stat3C) is targeted to the proliferative compartment of epidermis via the bovine keratin 5 promoter (K5.Stat3C mice), we recently demonstrated heightened sensitivity to two-stage skin carcinogenesis compared to non-transgenic littermates [13]. The gene discussed is STAT3; the disease is neoplasm.