MARCO and susceptibility to pneumonia measurement: A recent Danish study found that non-synonymous SNPs within MARCO were found at very low frequency (0.005-5%) within a Danish population, and in a study investigating whether MARCO was associated with chronic obstructive pulmonary disease (COPD) and lung infection in COPD patients, only one of these was associated with an increased risk of sepsis and none with pneumonia or COPD itself [42].