GSTP1 and gastric cancer: Therefore, an integrated analysis was performed to evaluate the ability of 11 tumor-related genes (p16, CDH1, RUNX3, MLH1, RASSF1A, p15, APC, DAPK, GSTP1, Reprimo, and MGMT) promoter methylation test using blood samples as a feasible biomarker in GC diagnosis and screening.