Diverse innate immune response molecules, such as serum C-reactive protein, erythrocyte sedimentation rate, ferritin, procalcitonin, amyloid A, IL-1β, IL-2, IL-2R, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNFα), interferon-gamma (IFNγ) and D-dimer, have been measured in COVID-19 patients. Here, IL2 is linked to COVID-19.