In human chronic myelogenous leukemia (CML), LSCs are consisted of composed of CD25-positive and -negative populations, while the CD25 positive cell can be stimulated and associate with IL-2 pos cells in the BM microenvironment, suggesting that targeting IL-2/CD25 axis may have a functional role in nurturing LSCs [23]. This evidence concerns the gene IL2RA and chronic myelogenous leukemia, BCR-ABL1 positive.