Clinical studies show that the levels of IL-2, TNF-α, IFN-γ, IP-10, MCP-1and other pro-inflammatory cytokines are significantly increased in severe or critical patients with COVID-19, while SARS-CoV-2 infection also increases secretion of anti-inflammatory cytokines (IL4 and IL10) [38]. The gene discussed is IL2; the disease is COVID-19.