PTX3 was previously shown to be involved in innate resistance to specific infections by opsonizing microorganisms (e.g. A. fumigatus conidia and Pseudomonas aeruginosa), directly (15, 28, 34, 35) or through ficolins and collectins (13, 36–38), and promoting complement-dependent phagocytosis. Here, PTX3 is linked to infection.