HNSCC cells belonging to the CSC population are distinguished by their high expression of certain surface proteins (for example, CD44, CD133), pluripotency-related transcription factors (SOX2, OCT4, Nanog), and increased aldehyde dehydrogenase (ALDH) activity (Cirillo et al. 2021; Krishnamurthy et al. 2010; Prince et al. 2007). The gene discussed is SOX2; the disease is head and neck squamous cell carcinoma.