TNF and pyoderma gangrenosum: A study of an inflammatory gene expression in pathological and non-pathological skin of patients with pyoderma gangrenosum showed that a variety of inflammatory mediators had been increasingly secreted in pyoderma gangrenosum lesions, such as IL-23, IL-1α, IL-1β, IL-6, IL-8, IL-12, and tumor necrosis factor (TNF)-alpha [3,7].