In chronic myeloid leukemia (CML), the TGF-β–PAI-1 axis was selectively increased in CML leukemic stem cells (LMCs) in the bone marrow, leading to expansion of the therapeutic options of tyrosine kinase inhibitors (TKIs) by blockade of PAI-1 [55]. This evidence concerns the gene SERPINE1 and chronic myelogenous leukemia, BCR-ABL1 positive.