While leukemic cells were treated with combination of SAHA and decitabine (DAC), a methyltransferase inhibitor, p53-dependent apoptosis is triggered by the upregulation of Puma and p21 in CML-T1 cells, and p53-independent apoptosis is triggered by inhibition of survivin and upregulation of p21 in HL-60 cells. The gene discussed is BBC3; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.