FN1 and colorectal carcinoma: In particular, converging lines of investigation have identified bacterial pathogens that are not part of the normal intestinal microbiota, such as Fusobacterium nucleatum (Fn) [4] and Streptococcus gallolyticus (Sg) [5], as potential etiologic factors in CRC based on the over-representation of DNA sequences or even cultivable microorganisms in malignant tissues compared with normal colon specimens.