In summary, we observed down regulation of ARID1A mRNA expression and upregulation of TP53 and PDL1 mRNA expression in GC which was in turn significantly associated high-grade and advanced stage of tumor suggesting that lower ARID1A expression and higher expression of TP53 and PDL1 might play a definite role in the initiation and progression of GC. The gene discussed is TP53; the disease is neoplasm.