The IHC staining (Fig. 10), western blotting and RT-qPCR (Fig. 11) results found that except SERPIAN5, which was relatively low-expressed in HNSCC tissues, the other five genes (OLR1, PDGFA, S100A4, MSX1, and APOH) were all highly expressed in HNSCC tissues. Here, S100A4 is linked to head and neck squamous cell carcinoma.