PTCH1 and skin basal cell carcinoma: This finding was further supported by quantitative western blot analyses, which demonstrated increased levels of PTCH1 and GLI1 or CCND1 proteins upon tGLI2 and FHL2-GLI2 expression in all four cell models, although the increases in PTCH1 were not significant in the DAOY and BCC cells (Fig. 4d).