SMO and leukemia: For example, XL-139 can reduce the activity of HH signaling pathway, reduce cell proliferation, while induce apoptosis of esophageal cancer cells in vitro.447 XL-139 can inhibit amyloblastoma cells with SMO-L412F mutation resistant to vismodegib.448 XL-139 combined with gemcitabine can significantly inhibit the growth of CCC in the subcutaneous xenotransplantation model of mice.276 Two clinical studies were designed to explore the effect of XL-139 combined with dasatinib in the treatment of leukemia, but the trial failed to proceed as expected (NCT01218477, NCT01357655).