title: Amplification of dihydrofolate reductase genes in methotrexate-resistant cultured mouse cells.
mesh_terms: D000483:Alleles; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D004790:Enzyme Induction / Q000187:drug effects; D005796:Genes / Q000187:drug effects*; D008727:Methotrexate / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate