IL16 has been reported to involve in the HIV replication in macrophages, dendritic cells, and monocytes (Gao et al., 1997; Maciaszek et al., 1997; Amiel et al., 1999), we next detected PR8 M2 expression in alveolar macrophages (AM), interstitial macrophages (IM), dendritic cells (DC), monocytes (Mono), and neutrophils (Neu) in the lungs of WT and IL16 KO mice at day 2 post-infection. Here, IL16 is linked to infection.