After adjustment for age, BMI, CCI score, and multiple testing, men with severe COVID-19 had higher median (IQR) concentrations of serum IL-6 (61 [29-302] pg/mL vs 26 [9-57] pg/mL; P = .003) and hepatocyte growth factor (HGF; 994 [383-2308] pg/mL vs 330 [190-467] pg/mL; P = .002) compared with men without severe COVID-19. Here, IL6 is linked to COVID-19.