SOX9 and head and neck squamous cell carcinoma: To first investigate whether SOX2 and SOX9 predict survival, Kaplan-Meier curves were plotted for each individual TF, and showed an unfavorable disease-specific survival (DSS) for HNSCC patients with low SOX2 (Supplementary Figure S1A) and high SOX9 (Supplementary Figure S1B) expression.