FN1 and neoplasm: Previous work by our group and others demonstrated that patients with CRC tumours harbouring high levels of Fn have poorer survival5, that Fusobacterium colonizes regions of patient tumours with immune and epithelial cell functions supportive of cancer progression10, that Fusobacterium persists in metastatic disease6 and that microbiome modulation targeting Fn could change the course of this disease6,11.