For that, we made use of human stromal cell lines (HS5 and HS27a) and several AML cell lines, including HL60 (mutated for Nras and Cdkn2a), U937 (mutated for Pten and p53), and OCI‐AML3 (mutated for Nras and Dnmt3a). The gene discussed is PTEN; the disease is acute myeloid leukemia.