While a previous report found no clear role for MBL in pneumococcal infections (Brown et al., 2002), more recent studies found an important contribution for the lectin pathway in mice that do not express ficolins (Endo et al., 2012) or MASP-2 (Ali et al., 2012), which showed an increased susceptibility to pneumococcal infections and a reduced opsonizing capacity in non-immune hosts (Ali et al., 2012; Endo et al., 2012). This evidence concerns the gene MASP2 and pneumococcal infection.