Building upon previous research, our study reveals a novel interaction network between GC cells and tumor-infiltrating macrophages that GC cells induce metabolic reprogramming on macrophages by secreting LGMN externally, promoting macrophage polarization towards the M2 phenotype, thus reshaping the GC immune microenvironment and ultimately forming a tumor environment resistant to PD-1 mAbs. This evidence concerns the gene PDCD1 and neoplasm.