Among these CSC-specific antigens, a high expression of surface markers CD133, CD44, ABC-family transporter proteins such as ABCG2, transcription regulators Nanog, Oct4, Sox2 and ALDH activity were assigned for potential CSC populations in HNSCC [6, 10–12, 24, 25]. This evidence concerns the gene ABCG2 and head and neck squamous cell carcinoma.