CD8A and carcinoma of esophagus: Although infiltrated CD8+ T cells were found to serve as prognostic biomarkers for various cancers (e.g., squamous cell carcinoma, non-small lung carcinoma, and esophageal carcinoma) (9–11), no studies have assessed the potential function of infiltrated CD8+ T cells in the prognosis of patients with ccRCC, to the best of our knowledge.