One characteristic that makes gastric cancer (GC) against other cancers is the intricate immune system's reaction, particularly to tenacious inflammation. Consequently, the immunological function is essential to the growth of this malignancy. Tumor immunotherapy has yielded several encouraging outcomes, but despite this, different patients continue to not respond to treatment, and a far larger number become resistant to it. Also, activated CAR-T cells express a majority of immunological checkpoint factors, containing PD1, CTLA4, and LAG3, which counteracts the anti-tumor actions of CAR-T cells. Moreover, cytokine release syndrome is one of the possible adverse responses of CAR-T cell therapy. Therefore, producing universal allogeneic T lymphocytes with potent anti-tumor activity is essential. This study demonstrates current research on this cutting-edge technology, including the composition and mode of action of CAR-NK and CAR-T cells in GC. Also, in this study, we examined recent studies about various specific GC biomarkers that target CAR-T cells and CAR-NK cells.