CXCL8 and influenza: Plasma IL-6 and IL-8 have been shown to correlate strongly in large pediatric and adult influenza cohorts, albeit typically with G-CSF and MIP-1α as well (24); in contrast, among COVID-19 samples, G-CSF clustered with IL-1α, IL-9, and TNFα (module 3), whereas MIP-1α clustered with 13 other cytokines, including several ILs and IFN-α (module 5).