ACRG classified GC into four molecular subtypes: microsatellite-instable (MSI), microsatellite-stable with epithelial–mesenchymal transition (EMT) expression (MSS/EMT), microsatellite-stable with activated TP53 (MSS/TP53+), and microsatellite-stable with TP53 functional loss (MSS/TP53−). Here, TP53 is linked to gastric cancer.