Reverse transcription polymerase chain reaction (RT-PCR) analysis found that BCL11A was down-regulated during myeloid differentiation of HL60 cells induced by all-trans-retinoic acid [4], and similar results were observed in K562 cells treated with butyric acid [67], indicating that high level of BCL11A may cause leukemia by block myeloid differentiation. Here, BCL11A is linked to leukemia.