Based on the expression of SOX2 and SOX9, we sub-divided the HNSCC-TCGA data into four cohorts: SOX2High/SOX9Low, SOX2High/SOX9High, SOX2Low/SOX9High, and SOX2Low/SOX9Low (Fig. 5g). This evidence concerns the gene SOX2 and head and neck squamous cell carcinoma.