1. Gastric cancer, cytotoxin-associated gene A–positive Helicobacter pylori, and serum pepsinogens: An international study 
Penelope M. Webb, Jean E. Crabtree, David Forman 
Gastroenterology 
Volume 116, Issue 2, Pages (February 1999)
DOI: /S (99)
Copyright © 1999 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Mean PgA/PgC ratio, adjusted for age group and sex, by study center. ▨, H. pylori negative; ■, H. pylori positive/CagA negative; □, H. pylori positive/CagA positive.
Gastroenterology  , DOI: ( /S (99) )
Copyright © 1999 American Gastroenterological Association Terms and Conditions