CD8A and oral cavity cancer: <i>In vitro</i> experiments evaluated the impact of advanced glycation end products (AGEs) on oral squamous cell carcinoma (OSCC) viability and CD8+ T cell function.<h4>Results</h4>Genetically elevated HbA1c was causally associated with the risk of oral cavity cancer (OR = 0.9993, 95% CI: 0.9988-0.9997, P = 0.0021).