Genetic and epigenetic alterations frequently found in gastric cancers, including amplification of genes involved in RAS-ERK signaling (KRAS, FGFR2, EGFR, ERBB2, and MET),182 gain of function of the CTNNB1 gene (encoding β-catenin),183 and loss of function of the TP53 gene (encoding p53) and the CDH1 gene (encoding E-cadherin),184–187 may play key roles in the functional compensation of CagA-directed cancer hallmarks. The gene discussed is TP53; the disease is gastric cancer.