This study aimed to systematically evaluate the clinical relevance, molecular characteristics, immune-related features, and biological function of RRN3 across cancers, with a particular focus on gastric cancer (GC).<h4>Methods</h4>Public databases were used to analyze RRN3 expression, clinicopathological associations, survival outcomes, ROC curves, genomic alterations, epigenetic and epitranscriptomic features, immune-related characteristics, drug-response profiles, and co-expression networks. Here, RRN3 is linked to cancer.