Recently, we found that the combination of ABL1 TKIs with OR-2100 (OR21), which we developed as the first orally available, single-compound DAC prodrug [25,26], induced synergistic anti-leukemic effects in a chronic myeloid leukemia mouse model [27]. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.