TP53 and gastric cancer: The Asian Cancer Research Group (ACRG) classified gastric cancer based on gene expression data into four subtypes: (i) microsatellite instability (MSI), (ii) microsatellite stable and epithelial‐to‐mesenchymal transition (MSS/EMT), (iii) MSS/TP53 active, and (iv) MSS/TP53 inactive (Cristescu et al, 2015).