We have reported that the noninvasive measurement of urinary β2-microglobulin or urinary L-FABP is related to the severity of COVID-19 and can be a useful predictive tool30,31 β2-microglobulin is elevated in inflammatory and cytokine-overload conditions, and L-FABP is elevated in hypoxia under inflammatory and cytokine-rich conditions. Here, FABP1 is linked to COVID-19.