Normal human cells can be transformed to anchorage-independent growth by transfection with DNA from MOLT-4 lymphoblasts, derived from a patient with acute lymphocytic leukemia. Cells were treated with polyethylene glycol 6000, and DNA was administered as a calcium phosphate coprecipitate . The transforming activity of MOLT DNA was inactivated by treatment with DNase or by the restriction enzymes Bgll or BamHl but not by EcoRV . DNA from transfected colonies can transform human recipient cells to anchorage-independent growth; the transforming ability and anchorage independence are maintained stably for at least 30 generations.