Initial studies by Zhan et al. revealed that elevated GLI1 contributed to acquired resistance and mesenchymal phenotypes in doxorubicin-selected multidrug-resistant chronic myelogenous leukemia (CML) K562 and vincristine-selected multidrug-resistant human cervical epidermoid carcinoma (KB) sublines [149]. This evidence concerns the gene GLI1 and chronic myelogenous leukemia, BCR-ABL1 positive.