Since SHH inhibition doesn’t affect physiological hematopoietic stem cells and can inhibits leukemic stem cells, exposure of CML leukemic stem cells to cyclopamine (SHH signaling inhibitor, CYC) reduces their number and inhibits their growth [65,66,67]. The gene discussed is SHH; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.