CD8A and breast carcinoma: F. nucleatum obviously decreased the accumulation of tumor-infiltrated T cells, and promoted the growth and metastasis of breast cancer.104 Moreover, F. nucleatum levels were inversely associated with CD3+ T cell density in breast cancer tissues,105 and the analysis of transcriptome and digital pathology also showed that intratumoral bacterial load was negatively correlated with T cell infiltration.106 Intratumoral Methylobacterium could induce the dysfunction of CD8+ tissue-resident memory cells in the tumor microenvironment of gastric cancer and promote tumor progression.107