title: Natural killer cell activity in syphilis.
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007157:Immunologic Surveillance; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D008875:Middle Aged; D013587:Syphilis / Q000276:immunology*