CCL2 and COVID-19: The NF‐κB signaling pathway is a central player and potential therapeutic target in severe COVID‐19 and CS, whose activation promotes the expression of a large number of inflammatory factors, including cytokines (IL‐1, IL‐2, IL‐6, IL‐12, TNF‐α, and GM‐CSF) and chemokines (CCL2 [MCP‐1], CXCL10 [IP‐10], CXCL9 [MIG], and IL‐8).139, 140