POU5F1 and esophageal squamous cell carcinoma: SOX2 gene, encoding a master regulator of pluripotency, lies within the third intron of a lncRNA, SOX2OT, which is transcribed in the same direction as SOX2. We recently reported that SOX2OT is upregulated along with master regulators of pluripotency, SOX2 and OCT4, in esophageal squamous cell carcinoma (ESCC).