IFNG and HIV infectious disease: These findings suggested that over expression of the surface Gal-9 on NK cells impairs their cytotoxicity but enables them to secret more IFN-γ, which may contribute to increased immune activation seen in chronic HIV infection although this is different from the previous results of recombinant Gal-9 to impair the functions which contain cytotoxicity and IFN-γ production, of NK cells [80].