IL6 and systemic-onset juvenile idiopathic arthritis: Interestingly, in patients with juvenile systemic idiopathic arthritis (SJIA), pulmonary involvement triggers a hyperinflammatory reaction and the appearance of secondary hemophagocytic lymphohistiocytosis (sHLH), as IFN, IL-1β, and IL-6 signature up-regulation can be observed [141,142].