IL21 and HIV-1 infection: In uncovering an antiviral IL-21–miR-29 axis that impairs early HIV-1 infection, our present study suggests that endogenous IL-21 and strategies that exogenously augment IL-21 or induce pre-existing cellular sources of IL-21 would be beneficial in not only promoting adaptive antiviral immunity but also contribute to limiting the magnitude of the initial HIV-1 infection.