IL2 and COVID-19: CRS was reported among patients with COVID-19; the former is characterized by increased levels of pro-inflammatory cytokines correlating with disease severity; these cytokines include interleukin (IL)-1β, IL-2, IL-6, IL-10, interferon (IFN)-γ, tumor necrosis factor (TNF), IFN-γ-inducible protein 10 (IP-10), granulocyte macrophage-colony stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 (MCP-1) [8–12].