TP53 and gastric cancer: A study based on gene expression data by the Asian Cancer Research Group (ACRG) has classified gastric cancer into four subtypes—microsatellite instable (MSI), microsatellite stable and epithelial-to-mesenchymal transition (MSS/EMT), TP53 active (MSS/TP53+) and TP53 inactive (MSS/TP53-) [4].