BAX and chronic gastritis: Bcl-2 (B-cell lymphoma-2) belongs to the intrinsic apoptotic pathway, and H. pylori infection is associated with over expression of both the Bcl-2 (which codifies the main anti-apoptotic protein) and Bax genes (pro-apoptotic), with Bax expression predominating in chronic gastritis and Bcl-2 expression in GC.