CD8A and carcinoma of esophagus: In this study, we established a nomogram model by integrating clinical indicators and CD39-expressing CD8+ T cells to more accurately predict the prognosis of patients with ESCC and further explored the potential of CD39-expressing CD8+ T cells as a therapeutic target of esophageal carcinoma by investigating the relationship between the expression of ENTPD1 and inhibitory immune checkpoint molecules in the TME.