In a prospective cohort study involving 147 prospectively followed COVID-19 patients and 216 healthy controls, MASP-2 levels exhibited significant positive correlations with the terminal complement complex (ρ = 0.3596, p < 0.0001), the lectin pathway recognition molecules ficolin-2 (ρ = 0.2906, p = 0.0004) and ficolin-3 (ρ = 0.3952, p < 0.0001), as well as with C-reactive protein levels (ρ = 0.3292, p = 0.0002) [281]. This evidence concerns the gene FCN2 and COVID-19.