Researchers at MD Anderson Cancer Center identified a mechanism by which tumor-infiltrating bacteria—principally Fusobacterium nucleatum—surround tumor epithelial cells and induce a reversible quiescent state that reduces transcriptional activity and immune visibility, enabling resistance to chemotherapy in oral and colorectal cancers. Spatial profiling and preclinical models showed bacteria accumulate between cancer cells, disrupt cell–cell communication, and correlate with poor treatment response. The study, published in Cancer Cell, links microbial localization with reduced expression of immune-detection genes and lower chemo sensitivity in patient cohorts. MD Anderson investigators suggested targeting tumor-associated microbes or their interactions with tumor cells could become a strategy to sensitize tumors to existing therapies and to design "microbe-aware" treatment regimens.