FN1 and rheumatoid arthritis: A large number of studiessuggest that Fn is closely related to the developmentsof systemic diseases, including rheumatoid arthritis, Alzheimer’sdisease, adverse pregnancy outcomes, and GI disorders such as IBD. In addition, Fn has gained attentionas emerging cancer-associated bacteria, overabundant in various types,including colorectal (CRC), pancreatic, esophageal, and breast cancers,, and associated with shorter patients survival.