Several class A scavenger receptors, in particular MARCO (or SCARA2), and SCARA4 (collectin-12), function in innate immune recognition of bacterial infections, while MSR1 (SCARA1, SR-AI, or CD204) has been shown recently to contribute to antiviral responses evoked by extracellular dsRNA [reviewed in 22]. This evidence concerns the gene MARCO and bacterial infectious disease.