IL6 and COVID-19: The random effects results demonstrated that patients with severe COVID-19 had significantly higher levels of CRP [SMD = 3.26 mg/L; (95% CI 2.5, 3.9); p<0.05; I2 = 98.02%; PHeterogeneity = 0.00], TNFα [SMD = 1.78 ng/mL; (95% CI 0.39, 3.1); p=0.012; I2 = 98.2%; PHeterogeneity = 0.00], and IL-6 [ SMD = 3.67 ng/mL; (95% CI 2.4, 4.8); p<0.05; I2 = 97.8%; PHeterogeneity = 0.00] compared with those with the mild form of the disease.