title: Liver-microsome S9 enzyme increase spontaneous background mutation frequency in the Ames Salmonella test system in the absence of any added mutagen.
mesh_terms: D000818:Animals; D008862:Microsomes, Liver / Q000378:metabolism*; D009152:Mutagenicity Tests; D009154:Mutation; D051381:Rats; D012486:Salmonella typhimurium / Q000235:genetics*