Analysis of the metabolic profile of the different strains in coculture with HT-29 or Caco-2 (human colon epithelial cell line) clearly showed that formate is a common Fn-derived metabolite that is secreted upon coculture between different human CRC-derived cells and Fn strains (Fig. 2f and Extended Data Fig. 3d). This evidence concerns the gene FN1 and colorectal carcinoma.