GSK3B and esophageal squamous cell carcinoma: Based on IHC results of serial tissue sections of ESCC, the protein level of p-AKT (T308), p-AKT (S473), EpCAM, and β-catenin was up-regulated; meanwhile, p-GSK3β (Tyr216 + Tyr279) and p-GSK3β (Ser9) are relatively low (Figure 5a).