Epidermal cell thymocyte-activating factor.

ETAF appears to have a multiplicity of divergent biologic effects: enhancement of thymocyte proliferation, stimulation of cells in the hypothalamus to mediate fever, stimulation of leukocyte chemotaxis, stimulation of hepatic synthesis of acute-phase proteins, induction of muscle proteolysis, augmentation of IL-2 production, and fibroblast and keratinocyte growth stimulation (Fig 4). However, it is unclear whether these divergent activities are mediated by one single cytokine, as is true for other hormones, or whether these divergent activities are mediated by several different but closely related cytokines, as is the case with interferons. In either case, ETAF, like IL 1, may play an important role in local cutaneous and systemic inflammatory and immunologic events.