Multiplex measurements of immune response proteins in antemortem plasma samples from patients with COVID-19 (n = 6 patients sampled up to four times before death; n = 11 samples total) demonstrated that concentrations of IFN-related proteins IFNLR1, DDX58, and leukemia inhibitory factor were significantly (P < 0.05) elevated compared to normal healthy volunteers (n = 10) (fig. Here, LIF is linked to COVID-19.