However, recent evidence suggests that the IGF and the Wnt signaling pathways are the likely candidates, as the insulin-like growth factor gene (Igf1), IGF pathway binding proteins and Wnt signaling molecules in the stroma were similarly modulated to Gli1 and Ptch1 in Hh inhibitor-treated tumour xenografts [90]. The gene discussed is PTCH1; the disease is neoplasm.