Lamina propria expression of bak has been shown to gradually increase over 20 wk of infection by H. pylori in mice (4, 11), and expression of bcl-2 family members is also altered in hypergastrinaemic mice, which may be a significant factor responsible for their increased susceptibility to H. felis-induced gastric carcinogenesis (7, 38). Here, BAK1 is linked to infection.