Following are the CytoHubba outcomes of hub genes in gastric cancer: DNA polymerase epsilon, catalytic subunit (POLE), mitotic checkpoint serine/threonine-protein kinase BUB1 beta (BUB1B), DNA polymerase delta subunit 4 (POLD4), complement 3 (C3), Bloom, Syndrome, RecQ helicase-like (BLM), chaperon containing TCP1 subunit 7 (eta) (CCT7), pre-mRNA processing factor 31 (PRPF31), APEX nuclease (multifunctional DNA enzyme repair 1), proteasome (prosome, macropain) subunit alpha type 7 (PSMA7), and cell division control protein 45 homolog (CDC45). This evidence concerns the gene APEX1 and gastric cancer.