Peripheral blood or bone marrow cells from patients with JMML were infected with a lentiviral vector expressing an inducible construct of all four Yamanaka factors. Induced iPSC clones were identified, and selected clones were differentiated into hematopoietic cells by using established protocols. Cells with JMML-like phenotypic and functional qualities were detected through several assays, including signal transduction analysis and responsiveness to growth factors. These cells were responsive to chemicals that inhibit certain signaling pathways. In future studies, these JMML-like cells can be tested for in vivo engraftment in immunodeficient mouse models and for more detailed molecular analysis.