Furthermore, there has been evidence showing that H. pylori triggers IL-8 and IL-6 induction upon infection of human endothelial cells (Ding et al., 1997; Innocenti et al., 2002) but the molecular mechanisms involved remained unclear, with no clear correlation observed between cagPAI status and the extent of IL-8 or IL-6 induction in primary human umbilical vein endothelial cells (HUVECs) (Innocenti et al., 2002). This evidence concerns the gene IL6 and infection.