FN1 and colorectal carcinoma: Recently, a new model of CRC pathogenesis was developed involving the bacterial riboflavin synthase from the enriched colorectal bacteria, i.e. Fn. Its role in CRC development may be attributed to microbe-derived riboflavin metabolites activating mucosal-associated invariant T-Cell (MAIT) (Li et al., 2020), which produce proinflammatory cytokines and cytotoxic molecules integral to the pathological process of CRC (Wang et al., 2022).