TP53 and gastric adenocarcinoma: After conducting a comprehensive analysis of the gene expression levels of 300 gastric adenocarcinomas in 2015, the Asian Cancer Research Group (ACRG) proposed a new gastric cancer molecular classification that comprised four molecular subtypes: MSI-H, MSS/EMT, MSS/TP53 mutant (MSS/TP53+), and MSS/TP53 wild-type (MSS/TP53–) subtypes [22].