TNF and systemic-onset juvenile idiopathic arthritis: Autoinflammatory diseases, such as systemic juvenile idiopathic arthritis (sJIA), familial Mediterranean fever (FMF), mevalonate kinase deficiency (MKD), cryopyrin associated periodic syndrome (CAPS) and tumor necrosis factor (TNF)-receptor associated periodic syndrome (TRAPS) exhibit systemic inflammation or organ specific inflammation caused by dysregulation of the innate immune system.