SOX2 and head and neck squamous cell carcinoma: In the case of head and neck squamous cell carcinomas, initial studies by Lee et al showed that SOX2 expression is correlated with poor prognosis and a nearly 5-fold higher risk of recurrence [49], but subsequent studies by Bayo et al determined that SOX2high tumors had a median progression-free survival of 51 months compared to SOX2low tumors (16 months) and that SOX2high tumors had a > 110 month improved overall survival compared to SOX2low tumors [65].