As shown in Figure 1A, SOX2 expression was detected in 3 of 6 kinds of lung SCC cells, in 2 of 4 kinds of pulmonary adenocarcinoma cells and in all kinds of esophageal SCC cells, while expression of SOX2 was not detected in normal human foreskin fibroblast HFF1 and normal human lung fibroblast NHLF and human umbilical vein endothelial cells (HUVEC). Here, SOX2 is linked to esophageal squamous cell carcinoma.