SOX2 and head and neck squamous cell carcinoma: To evaluate the prognostic value of SOX2 signature and clinicopathological variables (e.g. patient age, sex, smoking status, alcohol consumption, anatomic site, primary tumour stage, lymph node (LN) metastasis, and TNM stage) of patients with HNSCC, we performed univariate and multivariate Cox proportional hazards regression analyses using clinical data of patients in the TCGA and Leipzig cohorts (n = 725).