BCL2 and acute promyelocytic leukemia: These cancer cells included the histiocytic lymphoma U-937, the acute promyelocytic leukemia HL-60, the acute lymphoblastic leukemia MOLT-3, the pre-B NALM-6, the cell line over-expressing the human Bcl-2 protein (U-937/Bcl-2), and the melanoma SK-MEL-1 cell line.