IL6 and COVID-19: In a retrospective analysis of 324 patients with COVID-19 acute hypoxemic respiratory failure, Xu et al. reported that age ≥60 years, platelet count < 125x109/L, interleukin 6 > 7.0 pg/mL measured at initiation of HFNO, and ROX index of < 5.31 within four hours of HFNO initiation predicted HFNO failure [15].