CD4 and esophageal squamous cell carcinoma: While the predictive value of baseline CXCL13+ cells requires further investigation, elevated levels of CXCL13+ CD8+ or CD4+ T cells may predict a favorable PPCT response, as indicated by recent findings from an ESCC neoadjuvant immunochemotherapy study.43 This trial offers the first single-cell transcriptomic analysis of PPCT’s impact on CD4+ T cells in ESCC TME.