IL10 and macrophage activation syndrome: MIS-C is a cytokine storm induced by COVID-19 virus with very high inflammation markers (CRP, procalcitonin, neutrophilia, lymphopenia), pro-inflammatory cytokine levels, mainly IL-6, and high IL-10, soluble IL-2 receptor, ferritin levels, and D-dimers58,59 and frequently fulfils criteria for macrophage activation syndrome (MAS) of children with juvenile idiopathic arthritis.60