POU5F1 and esophageal squamous cell carcinoma: Inhibiting the expression of OCT4 or Survivin in ESCC cell lines with the OCT4-shRNA or Sur-shRNA vectors resulted in a reduction in G2-phase cells and an increase in cell apoptosis, and co-suppression of OCT4 and Survivin by the Dual-shRNA vector resulted in an enhanced effect.