OSM and COVID-19: OSM (oncostatin M, a positive regulator of IL-6 signaling) and EN-RAGE (S100A12, a biomarker of inflammation in acute respiratory distress syndrome [ARDS]) were increased in abundance in fatal COVID-19, positively correlated (R2 = 0.67; P = 0.0006) and elevated independent of whether the patient had received IMV (Figure E3B).