In order to study how integrin α6 promoted metastasis of ESCC cells, we then assessed the expression of p-Akt (T308) and p-FAK (Y397 and Y925) in 30-D cells transfected with siRNAs against integrin α6 under adherent condition (48 hr) or chemotaxis condition (1 hr); however, no detectable changes were observed in these three phosphorylated proteins (Figure 3A). Here, PTK2 is linked to esophageal squamous cell carcinoma.