Thus, we retrieved data from The Cancer Genome Atlas (TCGA) and analyzed the expression profile of ALDH1 (ALDH1A1), SOX2 (SOX2), and OCT4 (POU5F1) genes related to CSC in HNSCC, using the UALCAN tool [24,25]. This evidence concerns the gene SOX2 and head and neck squamous cell carcinoma.