Clinical tissue validation, in vitro rescue experiments, and in vivo xenograft assays were used to evaluate the involvement of RRN3 in GC progression.<h4>Results</h4>Pan-cancer analysis showed that RRN3 was upregulated in multiple tumor types, including GC, and that high RRN3 expression was associated with unfavorable overall survival in several cancers. The gene discussed is RRN3; the disease is gastric cancer.