DAPK1 and gastric cancer: As shown in Fig. 3, the pooled OR revealed that DAPK promoter methylation was significantly lower in patients with early gastric cancer than in patients with advanced gastric cancer under a fixed-effects model (I2 = 39.4%, OR = 0.69, 95% CI = 0.49–0.96, P = 0.03), which indicated that DAPK promoter methylation may have an increased risk in patients with advanced gastric cancer.