GLI1 and skin basal cell carcinoma: To test whether tGLI2 and the FHL2-GLI2 fusion proteins would activate GLI-responsive (RE) elements akin to wild-type GLI2, we performed a luciferase reporter assay with a specific GLI-RE containing GLI DNA binding sites in HEK-293, DAOY and BCC cells stably expressing empty vector, wild-type FHL2, wild-type GLI2, tGLI2, and FHL2-GLI2 (Fig. 5b, Supplementary Fig. 8).