Natural killer cells and their possible roles in host resistance against tumors.
D000818:Animals; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology*; D051379:Mice; D009369:Neoplasms / Q000276:immunology*; D009374:Neoplasms, Experimental / Q000276:immunology; D051381:Rats