IL6 and COVID-19: To investigate how D-dimer contributes to the disease progression of a COVID-19 infection, we observed that the D-dimer level exhibited moderate correlations with NLR (R = 0.5195, p < 0.001; Figure 1A; Table 1) and IL-6 (R = 0.543, p < 0.0001; Figure 1B, Table 1) in COVID-19 infected patients.