MARCO and fungal infectious disease: Moreover, given that MARCO appears to define a discrete subset of CXCL2-expressing alveolar macrophages with elevated pro-inflammatory features in the context of fungal infection (52), it will be of interest to determine if all alveolar macrophages are equal in their ability to eliminate S. pneumoniae or if an analogous CXCL2+ subset with superior anti-bacterial capacity exists in this context.