We report here on three novel observations: (i) the decrease of serum concentrations of two proteins of the lectin pathway during the acute phase of ischemic stroke; (ii) an inverse correlation of ficolin-3 levels obtained 3-4 days post-admission with the severity and outcome of acute ischemic stroke; (iii) the independent effect of low ficolin-3 and high CRP levels on the outcome of the disease. The gene discussed is FCN3; the disease is ischemic stroke.