CCNE1 and gastric adenocarcinoma: We also observed frequent PIK3CA mutations, associated with the EBV+ subtype, in gastric adenocarcinoma and EA, with a decrease in CCNE1-amplified versus nonamplified gastric adenocarcinoma (1.9% vs. 9.2%, P = 0.01) and a similar frequency in CCNE1-amplified versus nonamplified EA.