Dajnoki et al. demonstrated that the dermal production of IL-23 and TNF-a was significantly enhanced only in the lesional HS skin together with significantly increased T cell, dendritic cell and macrophage influx and elevated IL-12, IFN-c, IL-17A, IL-10, TGF-b and CCL20 expression levels. The gene discussed is IL23A; the disease is histiocytic sarcoma.