SHH and neoplasm: This was not always the case, as deletion of Shh enhanced disease progression and reduced CAF content in a PDAC model,9 and activating Hh signalling in fibroblasts markedly reduced tumour load and disease progression in a colon cancer model.62 Hh-signalling CAFs therefore appear to act as both tumour promoters and tumour suppressors, with the specific factors that predict this behaviour across multiple cancer types remaining unknown.