Researchers at the University of Arizona have identified a genetic variation that could help signal when patients with a specific bacterial infection could develop stomach cancer.

The bacteria Helicobacter Pylori is the primary cause of some types of stomach cancer. According to Mayo Clinic, more than half of all people may have the bacteria, but most don’t experience illnesses.

Dr. Juanita Merchant is a UA professor and study senior author. She said in a press release that some people have genes that signal more aggressive responses from their immune system.

That can lead to some complications. Merchant cited data that said between 1% and 3% of people with the bacteria develop gastric cancer.

Constant inflammation is believed to be a cause for gastric cancer, and Merchant said the gene could signal which patients are more likely to develop it.

The study was published in the journal Gastroenterology.