TNF and COVID-19: Figure 3 demonstrates a strong negative correlation between IL-6 and the percentage of lymphocytes in COVID-19 patients, with a strong correlation coefficient (R2 = 0.814) (p < 0.001). However, the association between the percentage of lymphocytes in COVID-19 patients and IFN γ and TNF-α is weaker (R2 = 0.0147, and 0.0089, respectively).