Recently, several groups have explored the responses of human monocyte-derived macrophages to avian and/or seasonal flu viral infection using a genome-wide approach [16] [17] [18] . Avian H5N1 and human H1N1 and H3N2 viruses induce increases in similar groups of genes despite the stronger response induced by pathogenic avian viruses compared to seasonal flu viruses in human monocyte-derived macrophages [16] [17] [18] [19] . However, the genome-wide response of resident human AM to influenza infection has not been reported. Our previous study showed that cultured primary human AM support a productive infection with H5N1 but not H1N1 and H3N2 influenza viruses though AM express both avian and human influenza receptors [3, 19] . However, human monocyte-derived macrophages support productive infection with both human and avian viruses [19] [20] [21] . These results suggest that the response of human AM to influenza might be different from the response of human macrophages derived from peripheral blood [22] .