TP53 and gastric cancer: Gastric cancer patients were classified into three categories based on the p53 mutation status as well as on the DNA methylation status of PGP9.5, NMDAR2B and CCNA1. These three categories were p53 mutant, p53 wild type with super‐high methylation (SHM) of the above three p53 pathway genes (p53 WT/SHM), and p53 wild type without SHM (p53 WT without SHM).