To verify that nuclear localization inhibition was due to inhibition of p65 phosphorylation, CML cell lines K562 and KCL‐22, the AML HL60 cell line, and primitive cells from a primary CML‐CP sample were treated with PTL at 7.5 and 10 μmol/L, for 6 hours. The gene discussed is CP; the disease is acute myeloid leukemia.