IDO1 and neoplasm: We discovered that they were mainly enriched in pathways and related functional pathways like Cytokine-cytokine receptor interaction, TGF-beta signaling pathway, and multi-multicellular organism process involving INHBE, TNFSF11, LIF, CXCL11, STC2, and IDO1 (Fig. S4A, B, Table S5), indicating that these 13 candidate targets might be involved in cell-to-cell communication within the GC tumor microenvironment.