IL6 and COVID-19: Indeed, longitudinal analyses to evaluate the dynamics of cytokine and chemokine production in plasma of COVID-19 patients reveal that in severe forms of COVID-19 there is an early systemic secretion (first week of onset of symptoms) of inhibitory mediators, including IL-10 and IL-1 receptor antagonist, whereas IL-6 and other inflammatory cytokines are significantly elevated only at later stages of severe COVID-19 illness [42].