In this study, AKAP5 and SLC2A3 in a 7-gene signature were relevant to the mechanism of immune cell infiltration in GC.AOAH-IT1 is a recently identified molecular marker of tumor, and CTLA4, LRRC8C, AOAH-IT1, NPC2, and RGS1 are involved in immune response and serve as molecular markers for therapeutic targets, prognosis, and immune cell immune infiltration in cancer. Here, NPC2 is linked to cancer.