IFNG and infection: Elimination of hematopoietic cells via cell-mediated cytotoxicity was described as an immune regulatory mechanism as well, e.g., during infection with lymphocytic choriomeningitis virus (LCMV).89,90 IFN-γ is an equally important effector molecule produced by NK cells since it activates antimicrobial functions in macrophages, increases antigen presentation and immunoglobulin (Ig) class switching.