The complement system functions as an immune surveillance system that rapidly responds to infection and can be activated via the classical pathway (CP), the lectin pathway (LP), or the alternative pathway (AP).9 In the LP, mannan-binding lectin (MBL) (or ficolins) binds carbohydrate arrays of mannan and N-acetylglucosamine residues on the surfaces of pathogens or virus-infected cells, resulting in the activation of MBL-associated serine protease-2 (MASP-2). This evidence concerns the gene MBL2 and infection.