Our studies revealed that miltirone could result in DNA strand breaks in human leukemia cells, as evident by the production of comet tails (Supplementary Fig. S2) and phosphorylation of H2A.X at ser 139, resulting in irreversible arrest of leukemia cells either at the G1 to S-phase boundary or G2/M-phase (Supplementary Fig. S3). This evidence concerns the gene H2AX and leukemia.