FOXP3 and esophageal squamous cell carcinoma: Although no association was found with lymph node metastasis in the previous TSCC and OHSCC cohort studies, there is still considerable amount of evidence available which indicates Foxp3 expression in breast cancer [14], gastric cancer [6], non-small cell lung cancer [15] and esophageal squamous cell carcinoma [16] is correlated with tumor metastasis.