CD8A and breast cancer: Methylobacterium, family Methylobacteriaceae, is reported to be elevated in breast cancer tissue6,22,28 and the sentinel lymph nodes of breast cancer patients, and associated with increasing cancer stage.31 Intratumoral Methylobacterium has been significantly associated with worse prognosis in gastric cancer, with a causal role via reducing CD8+ T cell response at the tumor site.39 In prostate cancer, M. radiotolerans is overrepresented in the tumor microbiome, and negatively associated with staging.40