S100A8 and COVID-19: patient cohorts and specifically analyzed samples collectedfrom patients at the time of admission to emergency departments.2,9,10,12,23,24 We have previouslyobserved 2-fold variations in serum S100A8/A9 levels in active tuberculosispatients in different geographical cohorts.25,26 Therefore, the reported predictive capacities and threshold valuesof serum S100A8/A9 for the prognostication of COVID-19 patients fromnon-U.S.