Infection in vivo is associated with lower expression of p53 and p21 and higher H-ras expression in gastric mucosa. Moreover, expression of NF-κB p65 subunit increased together with TNF-α expression are observed, and Bax expression was lower while Bcl-2 expression was higher. These data indicate that persistent infection is associated with aberrant expression of multiple proto-oncogenes in gastric mucosa of immunodeficient mice suggesting its potential influence on malignant transformation. [164]. This evidence concerns the gene BCL2 and infection.