In tumours from Ptch1Col1(het) mice, Gli1 transcripts were enriched in the stromal compartment as expected (Supplementary Fig. 6c,d), yet the amount of stroma did not differ significantly between tumours from control animals and those from Ptch1Col1(het) mice, as assessed by IF (Supplementary Fig. 6e). Here, GLI1 is linked to neoplasm.