Western blot analysis demonstrated a low or barely detectable level of SPRR1B expression in all the 10 primary HNSCC tumors (1 WDSCC, 6 MDSCC and 3 PDSCC, Table S1) exhibiting high level of MDA-9/Syntenin expression compared to the normal counterparts (Figure 4F). Here, SPRR1B is linked to head and neck squamous cell carcinoma.