Compared with moderate cases, severe cases show markedly higher circulating levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10, and the soluble form of IL-2 receptor [4], exhibiting features similar to those of cytokine storm syndromes, such as macrophage activation syndrome [1]. The gene discussed is IL6; the disease is macrophage activation syndrome.