Gastric acid
The highest concentration that gastric acid reaches in the stomach is 160 mM in the canaliculi. This is about 3 million times that of arterial blood, but almost exactly isotonic with other bodily fluids. The lowest pH of the secreted acid is 0.8, but the acid is diluted in the stomach lumen to a pH between 1 and 3.
Stomach cancer
"Helicobacter pylori" infection is an essential risk factor in 65–80% of gastric cancers, but only 2% of people with Helicobacter infections develop stomach cancer. The mechanism by which "H. pylori" induces stomach cancer potentially involves chronic inflammation, or the action of "H. pylori" virulence factors such as CagA. It was estimated that Epstein–Barr virus is responsible for 84,000 cases per year. AIDS is also associated with elevated risk.