Leukemia L1210Leukemia P388Leukemia Virus, MurineLeukemia, ExperimentalMoloney murine leukemia virusLeukemia L5178LeukemiaTrimetrexateCell LineTumor Cells, CulturedPteroylpolyglutamic AcidsLeukemia, Myeloid, AcuteFolic Acid AntagonistsAKR murine leukemia virusCell Line, TumorFriend murine leukemia virusHL-60 CellsDrug ResistanceAbelson murine leukemia virusMethotrexateAntineoplastic AgentsCell DivisionCell SurvivalLeukemia, LymphoidLeukemia, MyeloidLeukemia, Lymphocytic, Chronic, B-CellBase SequenceRetroviridae InfectionsMolecular Sequence DataLeukemia, Myelogenous, Chronic, BCR-ABL PositiveDoxorubicinLeukemia, Monocytic, AcuteCell Line, TransformedRauscher VirusK562 CellsApoptosisGene Expression Regulation, LeukemicLeukemia, T-CellCell DifferentiationStructure-Activity RelationshipMice, Inbred AKRRNA, MessengerPrecursor Cell Lymphoblastic Leukemia-LymphomaLeukemia, Promyelocytic, AcuteRetroviridaeTransfectionLeukemia, Megakaryoblastic, AcuteLeukemia, B-CellXenotropic murine leukemia virus-related virusMink Cell Focus-Inducing VirusesDrug Screening Assays, AntitumorNeoplasm Proteins