In addition, using an SCID mouse xenograft model of HNSCC, suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, significantly enhanced the anti-tumor activity of cisplatin treatment with no additional systemic toxicity and significantly decreased tumor metastasis and NANOG expression, a marker of stemness. This evidence concerns the gene HDAC9 and head and neck squamous cell carcinoma.