MMP9 and COVID-19: Considering all COVID-19 patients in terms of hospital admissions, positive correlations between the plasma levels of MMP-9 and WBC absolute count (ρ = 0.4794, p < 0.0001) (Figure 2A), N absolute count (ρ = 0.5403, p < 0.0001) (Figure 2B), NLR (ρ = 0.4261, p < 0.0001) (Figure 2C) and CRP (ρ = 0.2335, p = 0.0132) (Figure 2D) were found.