title: Dihydrofolate reductase activity of leukemia L1210 during development of methotrexate resistance.
mesh_terms: D000818:Animals; D002460:Cell Line; D004351:Drug Resistance; D007939:Leukemia L1210 / Q000201:enzymology*; D008297:Male; D008727:Methotrexate; D051379:Mice; D013154:Spleen / Q000201:enzymology; D013762:Tetrahydrofolate Dehydrogenase / Q000494:pharmacology*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate