CXCL8 and COVID-19: The levels of proinflammatory cytokines/chemokines such as interleukin 6 (IL-6), IL-8, interferon gamma (IFN-γ)-induced protein 10 (IP-10), and tumor necrosis factor alpha (TNF-α) are markedly elevated in the sera of severe COVID-19 patients (4, –, 9).