SOX2 overexpression is observed in different types of malignancies (28), including squamous cell lung carcinomas, squamous cell esophageal carcinomas (29), oral squamous cell carcinomas (30), melanoma, sinonasal carcinomas, Ewing’s sarcoma (28) and ameloblastic carcinoma (31). Here, SOX2 is linked to esophageal squamous cell carcinoma.