The major driver mutations of gastric cancers include human epidermal growth factor receptor-2 (HER2) 4, serine/threonine kinase 11 (STK11) 5, E-cadherin6, AT-rich interactive domain 1A (ARID1A) 7, Kirsten rat sarcoma virus (KRAS) amplification 8, A-T mutation (ATM), BRCA1 Interacting Protein 1 (BRIP1), RAD51 paralog D (RAD51D), or PIK3CA9. Here, RAD51D is linked to gastric cancer.