HGF and head and neck squamous cell carcinoma: Despite a lack of studies investigating the possible clinical correlates for Sulf1 or Sulf2 in HNSCC, there is evidence demonstrating that Sulf1 re-expression, which diminishes cell surface HSPG sulfation, interferes with both FGF2 and HGF signaling in SCCHN (33) and that desulfation of the cell surface HSPG by Sulf1 in SCCHN plays an important role in the control of tumor development (33).