For patients with moderate COVID-19, the levels of IL-10, IL-6, and TNF-α are within normal limits, whereas they are critically high in severe COVID-19 cases.[34] Macrophages are responsible for producing the cytokines involved in cytokine storm syndrome (CSS), which refers to the cascade of cytokine production resulting from an unregulated host immune response to different stimuli. This evidence concerns the gene IL10 and COVID-19.