SOX2 and oropharynx cancer: Comparing tumour sites revealed that 30.14%, 32.88%, 30.68%, and 6.30% of patients in the SOX2-high subgroup had oral cavity cancer, oropharynx cancer, larynx cancer, and hypopharynx cancer, respectively; and that 67.99% of patients in the SOX2-low subgroup had oral cavity cancer.