Our previous studies reported associations between lineages of M. tuberculosis, particularly the modern Beijing lineage, and TB clinical phenotypes.15, 17 Given a worldwide emergence of the M. tuberculosis Beijing strains,18 we hypothesized that variation in the scavenger receptor MARCO, which binds to Mycobacterium and enables phagocytosis by macrophages, might be preferentially associated with a specific lineage. The gene discussed is MARCO; the disease is tuberculosis.