TNC and granular cell tumor: In order to verify whether other already described markers also showed differences between GCT and GCT/PDB, we investigated the immunoreactivity of Tenascin C (TNC) and Epidermal Growth Factor Receptor (EGFR) as well as Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL), known to play a central role in GCTs (Figure 3).