This project uses transcriptome sequencing combined with proteomic analysis technology to find the mRNA and proteins differentially expressed between G-NENs and normal gastric mucosal tissues. Through bioinformatic analysis, potentially meaningful functional genes and their signaling pathways are screened, and the protein interaction network (PPI) of differentially expressed genes is constructed. Cytologically verified the function of the target genes and their regulatory pathways. By detecting the expression level of the target protein in clinical samples, the clinical application value of the target gene in G-NENs was clarified, and the possibility of serving as a molecular marker of G-NENs to judge the disease progression, treatment and prognosis was comprehensively evaluated. The ultimate goal is to discover the ultimate goal of target genes affecting the occurrence, development and prognosis of G-NENs.