A high incidence of EBV infection characterizes the clinical features of the MSS/TP53+ subtype (26.3%), whose molecular characteristics include activation of the TP53 pathway and high-frequency mutations in genes such as ARID1A, KRAS, PI3KCA, and SMA- and MAD-related protein 4 (SMAD4). This evidence concerns the gene TP53 and Epstein-Barr virus infection.