TNF and psoriasis: In the setting of decreased TNF-α, conventional dendritic cells are not able to activate the CD8+ T cells and cannot perform negative feedback on interferon-α. This causes an interferon-driven acute-phase immunologic reaction independent of T-cell activation [3]. Patients with TNF inhibitor-induced psoriasis show increased interferon-α expression in the dermal vasculature of their lesions [4].