IL-6 >142.5 pg/mL, IL-10 >10.8 pg/mL, IL1β > 4.68 pg/mL, sIL-2rα >804.5 pg/mL, IL-1Ra >88.4 pg/mL, and IL-18 > 144 pg/mL values were associated with the development of critical COVID-19 in the age-adjusted univariate analysis. Here, IL6 is linked to COVID-19.