The methylation status of 15 CpG sites at the promoter region of HOXA11 were analyzed using bisulfite sequencing PCR (BSP) in seven paired gastric cancer tissues along with their matched peritumor normal tissues, and it was found that peritumor normal tissues have markedly greater methylation level than their matched ones (P<0.01; Figure 8A-C). The gene discussed is HOXA11; the disease is gastric cancer.