Specifically, in participants who had clinical deterioration, the time course spline analysis showed that there was an aberrant immune response during the early part of SARS-CoV-2 infection (appendix pp 10–11), with significant downregulation of GM-CSF, IL-10, IL-12, IL-2, IFN-α2a, and IL-33 (figure 3B–G), suggesting a blunted early response to infection occurs in patients who then deteriorate. Here, IL2 is linked to infection.