S100B and HIV-1 infection: HIV-1 infection has been shown to increase the production of exosomes from infected macrophages (Kadiu et al., 2012), and Nef expression appears to significantly increase the number of late endosomes/MVBs (which account for exosomes biogenesis) in various cell lines, including human T lymphocytes (Sanfridson et al., 1997), HeLa, CIITA, and Mel JuSo cells (Stumptner-Cuvelette et al., 2003).