Studies have found that the high activity of protein kinase casein kinase 2 (PKCK2) in ESCC cells can induce E- to N-Cadherin transformation by directly or indirectly stabilising Snail proteins, thus leading to the down-regulation of E-Cadherin [88,89] (Figure 2). Here, SNAI1 is linked to esophageal squamous cell carcinoma.