ARAF and colorectal carcinoma: The enrichment of genes involved in this pathway could be relevant given the evidence of E. coli colonization in microsatellite unstable CRC (50) and of the genotoxic effect of the colibactin protein produced by pks-positive (pks+) E. coli strains which were enriched in stool samples and biopsy specimens from CRC subjects (51, 52).