SPI1 and B-cell chronic lymphocytic leukemia: Our results show that Mcl-1 and its transcription factor PU.1 were drastically down-regulated under R-CR8, S-CR8, and MR4 treatment, confirming works on Mcl-1 in other malignancies such as chronic lymphocytic leukemia [38], neuroblastoma [39], or multiple myeloma [40].