Moreover, an increased and imbalanced cytokine production—such as interleukin (IL) 17 and tumor necrosis factor (TNF) α—as well as an unopposed type I interferon production, and a change toward a helper T cell 1/helper T cell 2 profile, may all play a role in HS and psoriasis [4,5]. The gene discussed is TNF; the disease is histiocytic sarcoma.