Tumor cells were cultured on OP9-DL1, aMEM 20% FBS, IL7, FLT3-L. Cells were harvested and immediately spun down, and resuspended in PBS. Cells were fixed with 1% formaldehyde. Formaldehyde was quenched with 0.2 M glycine for 10 min. Fixed cells were stored at -80 degrees until use. 50000 cells were used for library preparation. Washed cells were resuspended in lysis buffer. After washing, cells were treated with transposition mix for 30 min at 37 degrees. Cycle of PCR amplification was determined by q-PCR. 100-800 bps of Libraries were selected from 2% agarose gel.