Considering both the interest on the role of MBL in the neonates' defense against infections and the presence of inconclusive results in the literature about the clinical significance of MBL deficiency in newborns [5–12], this study was scheduled in order to clarify the association of both functional and genotypic MBL deficiency with the causes of neonatal morbidity in a cohort of Greek NICU neonates. Here, MBL2 is linked to infection.