TNF and COVID-19: Analysis revealed a stronger positive correlation between the serum values of IL-33 and TNF-α (p = 0.000), IL-1β (p = 0.000), IL-6 (p = 0.000), IL-12 (p = 0.000), and IL-23 (p = 0.000) in COVID-19 patients with severe disease (Table 3).