Initial anti-SHH antibody staining revealed that cSCC tumor cells as well as stromal cells were SHH negative (data not shown) although the malignant epithelium of human pancreatic adenocarcinoma sections showed strong positivity and thus resembles the described SHH expression pattern (Thayer et al., 2003) (Supplementary Figure S1A). Here, SHH is linked to pancreatic adenocarcinoma.