CD8A and esophageal squamous cell carcinoma: The β-diversity characteristics of the intratumoral microbiome exhibit significant differences and can predict the therapeutic efficacy of neoadjuvant chemoimmunotherapy (NACI) efficacy, for example, Streptococcus bacteria accumulate in esophageal squamous cell carcinoma (ESCC), tumor-infiltrating CD8+ T cells increase, and respond well to anti-PD-1 therapy (2).