NALM-1/Cre cells are derived from the human NALM-1 macrophage cell line by stably integration of a constitutive Cre recombinase stably expression construct. NALM-1 cell line was generated from biphenotypic B myelomonocytic leukemia, has been widely used in cancer research and drug development. NALM-1/Cre cells stably express a nuclear localized Cre recombinase under the control of a CMV promoter.