title: DNA amplification and multidrug resistance.
mesh_terms: D000818:Animals; D004351:Drug Resistance; D005784:Gene Amplification; D005796:Genes / Q000187:drug effects; D006801:Humans; D008727:Methotrexate / Q000633:toxicity*; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate