CCL4 and COVID-19: We next assessed the potential of the 13 serum factors (IL-10, CCL2, CCL4, CXCL13, IL-1RA, IL-6, IL-15, VEGF-A, CXCL9, LIF, IL-1β, CXCL10, and HGF) and their relative cutpoint values to predict 30-day mortality among the COVID-19 patients enrolled in the combined LUH-1, LUH-2, and FCS cohorts.