POU5F1 and esophageal squamous cell carcinoma: Statistical correlation between OCT4 or Survivin expression and ESCC clinicopathological characteristics (gender, age, cell differentiation, tumor invasion depth, lymph node metastasis) was analyzed and revealed no significant differences between the OCT4- or Survivin-positive and OCT4- or Survivin-negative cases of ESCC (Table 2).