Preclinical studies have demonstrated that SMO inhibitors, including cyclopamine, vismodegib, erismodegob/sonidegib, and glasdegib, are capable of inhibiting CML bulk cells and LSCs either alone or in combination with BCR-ABL tyrosine kinase inhibitors (TKIs) [11,12,20,21,27]. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.