The methylation in the bone marrow and the gastric noncancerous and cancerous tissues. The mean level of methylation in the bone marrow (●), the H. pylori-negative gastric mucosa (■), the H. pylori-positive gastric mucosa (♦) and the baseline-level LOH cases (▲) was compared. Asterisks indicate significant differences between the noncancerous stomach tissues and the baseline-level LOH cancers (P < 0.05). Student's t test was used. Error bars indicate the standard error of the mean.