Because Bcl-2 is a crucial survival factor for CML stem cells that are not addicted to BCR-ABL (26, 101), the most important factor for disease recurrence and TKI resistance (102), DTT targeting both RTK (e.g., BCR-ABL) and Bcl-2 thus represents a rational approach to circumvent acquired TKI resistance (100, 101). This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.