ARID1A and gastric cancer: In addition, this panel did not cover several genes known to be mutated in 10% or more of gastric cancers, such as ARID1A, CREBBP, ERBB3, SMARCA4, and TGFBR2. Gene amplification was analyzed for 26 genes, including both oncogenes and tumor-suppressor genes, but was detected only in oncogenes, supporting the methodological validity.