While AMPs can block virus entry (e.g., by downmodulating chemokine receptors on target cells as reported for LL-37) (47) or directly target the HIV particle in vitro (e.g., by lactoferrin and elafin) (36, 48), they can also enhance HIV-1 infection in vivo through their immune modulatory effects (47). This evidence concerns the gene PI3 and HIV-1 infection.