CD40LG and fungal infectious disease: Cord serum has previously been found to possess IgM to β-glucan and chitosan (chitin that is about 80% deacetylated yielding a polymer this is about 80% glucosamine and 20% GlcNAc).[15] These antibodies were shown to protect mice from fungal infection.[15] Most cord samples also had high levels of IgM to rhamnose, a carbohydrate found in bacterial polysaccharides.