PTEN and esophageal squamous cell carcinoma: Activation of the PI3K/Akt/GSK-3β pathway is emerging as a central feature of EMT, with GSK-3β regulating the Snail expression through posttranslational modification.[20, 21] We hypothesize whether PTEN regulates Snail expression through PI3K/Akt/GSK-3β pathway in ESCC cells.