MBL2 and infection: Mannose-binding lectin (MBL) is a serum protein of hepatic origin belonging to a family of Ca2+-dependent collagenous lectins, most of which are components of the innate immune system or natural immunity.11,12 Mutations in the mannose binding protein gene have been associated with recurrent infections.13–15 A single gene, MBL2, located on chromosome 10, codes for human MBL.16,17 Mannose-binding lectin may exert its action through binding to mannose-rich, and N-acetyl-glucosamine oligosaccharides present on a variety of microorganisms.