Herein, we found that GC patients with low TUBA4B expression displayed shorter survival time than patients with high TUBA4B expression, and the AUC value based on plasma TUBA4B expression was 0.8075 (95% CI 0.7103 to 0.9047), implying that TUBA4B is an efficacious diagnostic and prognostic biomarker for GC patients. The gene discussed is TUBA4B; the disease is gastric cancer.