IL7 and HIV infectious disease: Notably, some degree of CD127 recovery on the surface of cells incubated in vitro in the absence of exogenous IL-7 is observed in T cells derived from either healthy donors or HIV-infected persons [5], [6], suggesting that some reversible mechanism of active down-modulation of CD127 surface expression appears to be operative in vivo and it is possible that this mechanism is influenced by HIV infection.