MSR1 and infection: In addition, on pathogen infection, SR-A initiates innate immune responses in the host not only by recognizing diverse pathogen-associated molecular patterns, including lipopolysaccharide (LPS), lipoteichoic acid, bacterial cytosine guanosine dinucleotide DNA and double-stranded RNA5, but also acting as a phagocytic receptor that mediates direct phagocytosis of various pathogenic bacteria, such as Listeria monocytogenes, Staphylococcus aureus, Streptococcus pyogenes and Neisseria meningitides6, 7, 8, 9, or antigens such as tumour heat shock proteins10.