TLR4 and COVID-19: Figure 4 depicts positive significant correlations of creatinine with TLR2 (A, p = 0.000), creatinine with TLR4 (B, p < 0.01), urea with TLR2 (C, p = 0.000), and urea with TLR4 (D, p = 0.000) in severe COVID-19 patients.