TNF and psoriasis: In contrast to this trend, most other cytokines associated with the psoriasis gene expression profile in the current study (Additional file 17a), and in previous studies [6, 8, 22, 74], appeared to primarily target non-specific DEGPs; such cytokines include TNF, interferon (IFN)-γ, IFN-α and IL-1-family cytokines (e.g., IL1-F8, IL1-F9 and IL-1A; Fig. 6a).