TNF-, IL-2, IL-6, IL1B, IL7, IL10, IFN-, GCSF, CXCL10, CCL2, ferritin, D-dimer, fibrinogen, leukocytosis, and C-reactive protein (CRP) levels are significantly higher in critically ill COVID-19 patients [78,79,80]. Here, IL7 is linked to COVID-19.