VHL and nonpapillary renal cell carcinoma: The results showed that mRNA levels of PTCH1, an inhibitor of Hedgehog pathway, were significantly lower in VHL-wt ccRCC cell lines while mRNA levels of transcription factor GLI1, a terminal effector of the Hedgehog pathway, were significantly higher in VHL-wt ccRCC cell lines compared to normal kidney cell lines (Fig. 4a, b).