• Self-renewal, colony formation, migration, and invasion in HNSCC [126]. • Associated with overexpression of the EMT-related transcription factors Snail and Slug in ACC [127]. • Strong correlation with advanced stages, aggressive clinicopathological behaviors, stem cell-like properties, drug resistance, and poor prognosis in HNSCC [82, 128]. The gene discussed is SNAI1; the disease is head and neck squamous cell carcinoma.