CD4 and esophageal squamous cell carcinoma: In other translational studies, Foxp3+ T cells in the TME of NSCLC were associated with poor OS (22), and in our study, a positive correlation between post-treatment Foxp3+ T cells/(CD4+ T cells) ratios and RVT was confirmed in the context of ESCC, suggesting a prognostic role of post-treatment Foxp3+ T cells/(CD4+ T cells) ratios.