In esophageal squamous cell carcinoma (ESCC), investigations into the impact of intratumoral microbiota on neoadjuvant chemoimmunotherapy (NACI) response revealed that Streptococcus enrichment correlates with improved treatment outcomes, including increased CD8+ T-cell infiltration and prolonged disease-free survival. This evidence concerns the gene CD8A and esophageal squamous cell carcinoma.