ICOS and gastric cancer: We identified 20 immunoinhibitors (ADORA2A,BTLA,CD160,CD244,CD274,CD96,CSFIR,CTLA4,HAVCR2,IDO1,IL10,KDR,LAG3,LGALS9,PDCD1,PDCD1LG2,PVRL2,TGFB1,TGFBR1, and TIGIT), 37 immunostimulators (CXCR4,ENTPDI,HHLA2,ICOS,ICOSLG,IL2RA,IL6,lL6R,KLRCI,KLRKI,LTA,PVR,TMEM173,TMlGD2,TNFRSF13B,TNFRSF13C,TNFRSF17,TNFRSF18,TNFRSF25,TNFRSF4,TNFRSF8,TNFRSF9,TNFSF13B,TNFSF14,TNFSF18,TNFSF4, and ULBP1) and 16 MHC molecules(MHC molecule: B2M,HLA-A,HLA-B,HLA-C,HLA-DMA,HLA-DMB,HLA-DOA,HLA-DOB,HLA-DPA1,HLA-DPB1,HLA-DQAI,HLA-DQA2,HLA-DQBI,HLA-DRA,HLA-DRB1, and HLA-E) significantly associated with CXCR4 in GC (Fig. 6A).