ALDH1A1 and oral cavity squamous cell carcinoma: In agreement with such possibility, recent studies have shown that high Aldh1a1 and Sox2 expression correlates with an undifferentiated and metastatic phenotype in oral squamous cell carcinomas [41] and that Sox2 depletion blocks the tumor-initiating ability of human melanoma cells expressing high levels of Aldh1a1 [14].