Leukemia L1210Leukemia P388Leukemia Virus, MurineLeukemia, ExperimentalHematopoiesisMoloney murine leukemia virusLeukemia L5178LeukemiaCell LineTrimetrexateTumor Cells, CulturedPteroylpolyglutamic AcidsLeukemia, Myeloid, AcuteFolic Acid AntagonistsAKR murine leukemia virusCell Line, TumorHematopoiesis, ExtramedullaryFriend murine leukemia virusHL-60 CellsDrug ResistanceAbelson murine leukemia virusMethotrexateCell DivisionAntineoplastic AgentsHematopoietic Stem CellsLeukemia, MyeloidCell SurvivalLeukemia, LymphoidLeukemia, Lymphocytic, Chronic, B-CellCell DifferentiationBase SequenceMolecular Sequence DataLeukemia, Myelogenous, Chronic, BCR-ABL PositiveRetroviridae InfectionsK562 CellsDoxorubicinLeukemia, Monocytic, AcuteGene Expression Regulation, LeukemicApoptosisCell Line, TransformedRauscher VirusLeukemia, T-CellRNA, MessengerStructure-Activity RelationshipRetroviridaeBone MarrowPrecursor Cell Lymphoblastic Leukemia-LymphomaLeukemia, Promyelocytic, AcuteMice, Inbred AKRTransfectionLeukemia, Megakaryoblastic, AcuteCells, CulturedFlow CytometryNeoplasm ProteinsBone Marrow CellsLeukemia, B-CellAmino Acid SequenceXenotropic murine leukemia virus-related virusMice, Inbred StrainsGranulocytesMink Cell Focus-Inducing VirusesDrug Screening Assays, Antitumor