No significant difference in HHIP gene promoter region methylation was observed in the gastric cancer tissues and AGS cells (P>0.05), however, the HHIP gene promoter region methylation level was significantly lower in the adjacent normal tissues compared with the gastric cancer tissues and AGS cells (17.7±3.59 vs. 62.9±6.14 and 99.7±0.67%; all P<0.05). The gene discussed is HHIP; the disease is gastric cancer.