Figure 3 Proliferation status of gastric corpus mucosal cells using Ki‐67 immunohistochemistry. There was a characteristic Ki‐67 staining pattern restricted to the proliferating neck zone in the mucosa of wild‐type (WT) mice (A). In contrast, the proliferative compartment was considerably expanded in Aα^0/0 mice (B). At six months old, the height of the upper, neck, and lower zones in Aα^0/0 mice, as divided by Ki‐67 signals, was significantly greater than that in WT mice (p<0.001) (C). Results are expressed as mean (SEM). n = number of mice used. ^∗∗∗p<0.001 compared with the same mucosal zone of six month old WT mice by the Student's t test. Original magnification: A, B ×100.