The Hh signaling pathway is active in MC lines and in primary MCs from patients with MCL. (A) Relative gene expression of GLI1, GLI2, and GLI3 in WBM from patients with KIT A502_Y503dup MCL (MCL1), KIT WT MCL (MCL2), KIT D816V MCL (MCL3), KIT S501_A502dup MCL (MCL4), KIT D816V ASM (ASM1), or KIT WT ASM (ASM2) and from 3 patients with KIT D816V ISM (ISM1-3) and from 1 patient with KIT D816V CM (CM). (B) Immunofluorescence analysis of primary MCs from patients with MCL2, MCL3, or MCL4 and from 2 healthy controls. Note the increase of GLI1 or GLI2 and GLI3 in patients with MCL compared with healthy controls. (C) Quantification of GLI1, GLI2, and GLI3 expression in all patients. (D) Immunoblots with protein extracts from cord blood–derived MCs (Primary MC1 and MC2) and ROSA KIT D816V, stained with GLI1, GLI12, and GLI13 antibodies. (E) Immunoblots of ROSA and HMC1 cell lines stained with GLI1, GLI12, and GLI13 antibodies. (F) Immunoblots of ROSA KIT WT cells cultured in different conditions: standard, without (−) or with (+) SCF, and stained with GLI1, GLI3, and Bcl2. (G) Relative gene expression of GLI1 and KIT in HMC1.2 stimulated with SAG. (H) Relative quantification of GLI3A/GLI3R ratio. *P < .05, **P < .01, ***P < .001, ****P < .0001. PC, proteolytic cleavage domain; TA, transactivation domains; ZNF, zinc finger domain.