TNF and skin disorder: Tumor-bearing poly (I:C)-treated Mx1-Cre;Ptpn2fl/fl mice developed dermatitis (Fig. 10d), had splenomegaly associated with the expansion of T cells and myeloid cells (Fig. 10e), had systemic inflammation as reflected by increased serum levels of the proinflammatory cytokines IL-6, IFNγ and TNF (Fig. 10f) and developed overt liver damage as reflected by the increased circulating levels of ALT and AST (Fig. 10g) and the presence of lymphocytic infiltrates and fibrosis (Fig. 10h).