PIK3CA and gastric cancer: Based on a comprehensive molecular characterization of gastric cancer, Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been identified as one of four gastric cancer subtypes and includes the following distinct characteristics: CDKN2A promoter hypermethylation, recurrent PIK3CA mutations, PD-L1/2 overexpression, and sometimes immune cell signaling activation [1].