The Hh pathway is essential for MC transformation. (A) Time course of the proliferation of HMC1.1 and HMC1.2 cell lines treated with increasing concentrations of sonidegib or DMSO. Cell confluence was measured by using live-cell imaging (IncuCyte). HMC1 proliferation (percentage confluence) is plotted against time (in hours). (B) Death of HMC1.1 and HMC1.2 cells treated with increasing concentrations of sonidegib or DMSO. (C) Immunoblots of HMC1.2 and HMC1.1 cells treated in the same conditions and stained with GLI1, GLI3, and Bcl2 antibodies. (D) Quantification of P-STAT3 in treated HMC1.2 cells by using a phosphokinase array. (E) Time-course of proliferation of primary MCs obtained from a patient with KIT D816V ASM treated with increasing concentrations of sonidegib or DMSO. (F) Death of primary MCs of a patient with KIT D816V ASM (ASM1) and of a patient with KIT S501_A502dup MCL (MCL4) treated with increasing concentrations of sonidegib or DMSO. (G) Immunoblots of the same patient’s primary MCs treated in the same conditions, stained with GLI3, GLI1, and Bcl2; the corresponding quantification of GLI3A/GLI3R relative protein expression is indicated. Data are from 3 independent experiments. *P < .05; **P < .01; ***P < .001; ****P < .0001.