ARID1A and Epstein-Barr virus infection: Since EBVaGC comprises 3.5–10% of gastric cancer with a half showing loss of ARID1A, the relative incidence of p53-positivity and EBV infection in non-neoplastic mucosa (25:2) appeared to correspond with that in gastric cancer, suggesting that both are precursors of each subtype of gastric cancer.