The lectin pathway, one of three known molecular pathways of complement activation (classical, alternative and mannose-binding lectin (MBL), also plays an important role in innate immune protection against A. fumigatus in immunocompromised patients [15], the pathophysiology of atherosclerosis in humans [16], myocardial infarction, coagulation, brain ischemic injury, and the innate immune response to pneumococcal infection in mice [17–19]. Here, MBL2 is linked to pneumococcal infection.