(A) Cell viability assay of human GIST cell lines at 72h after the indicated treatment. (B) Immunoblots of whole-cell lysates of GIST T1 cells 24h after the indicated treatment. (C) Tumor weight in KitV558Δ/+ mice treated for 2 weeks with vehicle (Veh), imatinib (Imat), G007-LK plus imatinib, or G007-LK alone. n=4–5 mice per group. Medians are indicated. (D) Immunoblots of whole-cell lysates from vehicle or treated KitV558Δ/+ tumors. (E) Representative H&E, Ki-67 staining and quantification in KitV558Δ/+ tumors after 2 weeks of the indicated treatment. Scale bar, 50 μm. Bars indicate means ± SEM. Student’s t test; *P < 0.05, **P < 0.01, ***P < 0.001.