As lectin pathway-associated PRM are constitutively present in the respiratory system (ficolin-3 synthesized by type II pneumocytes and ciliated bronchial cell, ficolin-1 produced by lung macrophages) or are transferred from the bloodstream to the infected sites [MBL and ficolin-2 detected in bronchoalveolar lavage fluid (BALF) from patients suffering from pneumonia or invasive aspergillosis, respectively], they may contribute to excessive inflammation and its detrimental effects. The gene discussed is MBL2; the disease is susceptibility to pneumonia measurement.