For instance, in our system SP upregulated the production of CCL20, a chemokine that was previously shown to be involved in promoting HIV-1 infection of the FGM through recruitment of Langerhans cells in vitro [60], and plasmacytoid dendritic cells in non-human primates already at day 1 post-infection with SIV [56,57]. Here, CCL20 is linked to HIV-1 infection.