WNT1 and cyst: We also have demonstrated that abilities of p53−/− C2mE and p53−/− Wnt1 gastric epithelial cells to form cysts were lower than for p53−/− Gan gastric epithelial cells, showing that the cyst-forming ability of p53−/− Gan gastric epithelial cells depends on both C2mE and Wnt1 activity (Fig. S2).