They found that although increased, IL-6 levels in severe and critical COVID-19 patients were 100 times significantly lower than in patients with CAR-T cell-induced CRS (n = 72 with CRS grade ≥ 3); 27 times significantly lower than in patients with sepsis (n = 5320) and 12 times significantly lower than in patients with ARDS unrelated to COVID-19 (n = 2767). Here, IL6 is linked to COVID-19.